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ELEMENTARY

ANATOMY AND PHYSIOLOGY,

FOR COLLEGES, ACADEMIES,

AND OTHER SCHOOLS.

BY

EDWAKD HITCHCOCK, D.D.,LL.D.,

AND

EDWARD HITCHCOCK, JR., MD.,

PBOFESSOBS IN A M H B B B T C O L X. E Q S.

REVISED EDITION.

NEW YORK:

IVISON, PHINNEY, BLAKEMAN Ss CO.,

CHICAGO: a 0. GRIGGS & CO

18 68.

HARVA'=>D UMIV'FRSITY
.SCHOOL OF MlC C . Z -:0 PUBLiC HEALTH

■?c

ibRARY

0 SEP 1937

p_c 6.1:^-^Ujlw,

h^':^.

Entered, according to Act of Congress, in the year 1860, by

IVISON & PHINNEY,

In the Clerk's Office of the District Court for the Southern District of New York.

■lbotbottpkd bt

Smith &i MoI>oi7aA&»

82 <fc 84 B<Mkiium-tt

PREFACE.

This work is offered to the public in the hope that it has
some desirable features as a text-book, not found in any of the
able elementary works on Anatomy and Physiology now ex-
tant. One is, the introduction of more of microscopic anat-
omy than is usual. Another is, a large addition on Com-
parative Anatomy, which is now become a science of great
importance. A third is, the Religious Applications of these
sciences ; which, although all will acknowledge to be emi-
nently appropriate, we have found in no elementary treatise.

We make no pretensions to distinguished attainments or
reputation in these sciences, as a reason for writing this book.
But both of us have for a great number of years been in the
habit of hearing recitations and giving lectures upon them in
the College and the Academy, and we ought to know what
sort of a text-book is needed. But we dare not boast that we
have come up to our ideal. We have tried to give a condensed
yet clear exhibition of the leading principles and facts, which
are detailed in such works as Carpenter's Human Physiology,
his Comparative Physiology, Hassall's Microscopic Anatomy,
Griffith and Henfrey's Micrographic Dictionary, Peaslee's
Histology, Todd and Bowman's Physiological Anatomy, Wil-
son's and Gray's Anatomy, Draper's, Dunglinson's, and Dal-
ton's Physiologies, Van Der Hoeven's Zoology, and the works
of Cuvier, Owen, Agassiz, Wyman, Leidy, and Wagner on
Comparative Anatomy.

IV PREFACE.

Through the liberality of the publishers we are able to pre-
sent unusually full illustrations of subjects, which could other-
wise be only imperfectly comprehended by the learner.

Many of the drawings contain more minute details of
the parts represented than are described in the text. The in-
structor can require these to be recited or not, as he pleases,
according to the age and ability of the pupil. So as to the
parts on Comparative Anatomy, as they are distinctly sepa-
rated from the rest, they can, if desired, be passed over in re-
citation.

At the earnest solicitation of my son, my name stands first
on the title-page. But justice requires me to state that most
of the body of the work has been prepared by him. I have
supposed it most appropriate that it should be so, since he has,
and I have not, passed regularly through the medical school.
"Yet perhaps the public may have some confidence in my judg-
ment as a teacher for more than forty years, in shaping the
materials so as to be best adapted for purposes of instruction.
But aware, in some measure, of our deficiencies and imperfec-
tions, neither of us, in sending forth the work, feels it to be
beyond criticism and improvement. In a field so wide, where
so many are pushing their investigations, and the highest
authorities so frequently change their views, we do not ex-
pect to avoid all mistakes ; but in our successive editions,
we shall correct all errors which we find, and try to incorpor-
ate the new discoveries.

Edward Hitchcock.

Amherst College July, 1860.

CONTENTS.

Preliminaet Definitions kim Principles , . . . . 5

CHAPTER I.

Osteology and Syndesmology — Description of the Bones and

Ligaments ' 31

CHAPTER II.
Myology — ^Description of the Muscles 107

CHAPTER III.

Splanchnology — Description of the Digestive Organs 155

CHAPTER lY.

Angiology — Description of the Heart, Blood, and Blood- Vessels, 201

CHAPTER Y.

Pneumonology — Description of the Organs of Breathing... 244

CHAPTER YI.

Ichorology— Description of the Organs of Secretion 282

VI CONTENTS.

CHAPTER VII.

PA6B

Neurology — Description of the Brain and Nerves ^ 316

CHAPTER VIII.
The Inlets to the Soul — The Senses 36T

CHAPTER IX.
Religious Inferences from Anatomy and Physiology 420

PRELIMINARY

DEFINITIONS AND PRINCIPLES.

1. All the objects in the material world are divided into
Organic and Inorganic.

2. Cells, Membranes, and Fibers. — In organic bodies, the
matter composing them is arranged in the form of cells, mem-
branes, and fibers, variously combined. In inorganic bodies,
though the particles are often arranged with mathematical
precision in particular modes, cells, membranes, and fibers
are not formed.

3. Life. — The principle of life is always associated with or-
ganic, but never with inorganic bodies..

4. Examples of Organic and Inorganic Objects. — Or-
ganic bodies embrace Animals and Plants ; every thing else in
the material world is inorganic, as, air, water, minerals, rocks,
and soils.

5. Man the Head of the Animal Kingdom.— *' Man is
the end toward which all the animal kingdom has tended
from the first appearance of the Palaeozoic fishes." — Agassiz
and Gould.

6. Anatomy and Physiology. — Anatomy is the science that

Questions. 1 . Give the two kingdoms of tho material world. 2. What is the arrantco-
ment of matter in organic and inorganic bodies? 3. With which is life associated?
4. state some examples of organic and inorganic bodies. 5. Why is man placed at the
head of the animal kingdom ? 6. Define Anatomy.

6 H T T € n C 0 C K ' S ANATOMY

describes the different organs of animals. Phjsiologj describes
their functions, or uses. If the organs of man alone be de-
scribed, the science is called Human Anatomy and Physiology.
If the description embrace the lower animals, it is called Com-
parative Anatomy and Physiology.

7. Another definition of Anatomy, is the-^science of Organ-
ization ; and of Physiology, the science of Life.

8. Animal and Vegetable Anatomy anrth Physiology

There are also such sciences as Yegetaole Anatomy and
Physiology. Indeed, there is a strong analogy between the
organs of plants and animals, and their uses. Nor is it easy
always to draw the line between plants and animals, where
they approach the nearest to each other.

9. Intimate Connection of Anatomy and Physiology. —
Few writers confine themselves to the structure of animals,
when treating of their anatomy, but treat also of the function
of their organs ; and the same thing is still more generally
true of writers on physiology. We do not separate these
sciences in this treatise.

10. Fifteen Chemical Elements in the Human Body. — Of
the sixty-five chemical elements or simple bodies known to
exist, only fifteen have been found as normal constituents of
the human body. The following is the list : —

1. Oxygen, 6. Phosphorus, 11. Chlorine,

2. Hydrogen, 7. Calcium, 12. Fluorine,

3. Carbon, 8. Magnesium, 13. Silicon,

4. Nitrogen, 9. Sodium, 14. Iron,

5. Sulphur, 10. Potassium, 15. Manganese.

11. Carbon, Hydrogen, Oxygen, and Nitrogen.— The first
three of the above elements are found in all the solids and fluids
of the body, without exception. The first four occur in all the

What is Pliysiolofry ? When is tlio term comparative applied? 7. Give a more con-
cise definition of Anatomy and Physiology. 8. Describe animal and vegetable Diy-
siology. 9 Speak of the close relationship between Anatomy and Physiology. Stato
the whole number of cliemical Elements. 10. State those which are found in the human
body. 11. Where arc the firat three found? Nitrogen also ?

AND PHYSIOLOGY. ^

solid parts, and in all the fluids except fat. Thej form the
chief and most important ingredients in animals and plants.

12. Sulphur and Phosphorus, Magnesium, Soilium, Pot-
assium, Chlorine, Fluorine, Calcium, Silicon, Irou, Man-
ganese.— With scarcely an exception, these elements exist in
the hody as compounds; that is, t\yo or more of them are
combined, as in water, in oxjds, and in various salts. Sul-
phur and phosphorus exist in albumen and fibrine, as well as
in the brain, about lYTrth of its weight being phosphorus.
Bones are more than half made up of Phosphate of Lime, and
the J contain a small per cent, of Phosphate of Magnesia.
Sodium, in the form of a chlorid (common salt), is found in
cverj solid and fluid of the bodj. Potassium occurs as a
chlorid in the muscles, and as an oxjd in salts. Chlorine
forms chlorohjdric acid by combining with hydrogen ia the
gastric juice. Fluorine exists in the bones in a minute quan-
tity, combined with calcium. Silicon is found in small quan-
tities m hair, wool, and feathers, as silica. Iron forms about
the 2000th part of the blood, and it exists also in the muscles,
hair, and milk. Manganese, in small quantities, has been
detected in bone, and perhaps in the hair.

13. Copper, Lead, and Arsenic. — Copper, lead, and arsenic
have been detected in minute quantity in human flesh. . But
it is not probable that they are normal constituents.

14. Inferences. — From these facts we learn that our food
and drink should contain the fifteen ingredients above described.
Milk and eggs are the only articles that do contain them all ;
and hence, the importance of variety in diet. And the fact
that we are obliged to use ten mineral ingredients in our food,
shows the absurdity of a prevalent prejudice that no mineral
should ever be taken as a medicine.

15. Immediate Principles. — As they exist in the body, the

12. State in what organs Sulplnir and rhosphorns are found. What is ono of the prin-
cipal in;_'ie<lients of bones ? Where is Chlorine found ? Fluorine? Silicon? In what
parts of the tody is Iron fonn<l? 13. What is to be said of Copper, Lead ami Arsenic?
14. What should our food contaiu? Aro uiiaerul ingredients always poisonous? 15. Dc«
fme liaiuoUiate Principles.

8 HITCHCOCK'S ANATOMY

fifteen elements above described form a large number of com-
pounds, called Immediate Principles, or Organic Radicals.
They exist naturally, and can be separated anatomically, that
is, mechanically, from one another ; but the divisions can be
carried no further Avithout chemical decomposition. A few
elementary substances found in the system, as, oxygen, hydro-
gen, and nitrogen, are sometimes called Immediate Principles.

16. Immediate Principles Chemically Grouped. — We are
certain that eighty-four of these principles have been found in
the human system. If we group them according to their chem-
ical characters, they will fall into the following divisions.
Half of them are the result of the waste or metamorphosis of
the substance of the body ; lac other half exist independently
of any such change.

1. Gascons^ and not saline : Oxygen, Hydrogen, Nitro-
gen, Carbonic Acid, and Water.

2. Sails : Chlorids (2), Fluoride of Calcium, Hydrochlo-
rate of Ammonia, Carbonates (4), Bicarbonate of Soda, Sul-
phates (3^, Phosphates (7), Lactates (3), Oxalate of Lime,
Urates (5), Hippurates (3), Inosate of Potassa, Pneumate
of Soda, Taurochlorate of Soda, Hyocholinate of Soda, Gly-
cocholate of Soda, Oleate of Soda, Margarate of Soda, Stear-
ate of Soda, Caproate of Potassa, Soda, &c.

3. Acids: Lactic, Uric, Hippuric, Pneumic, Lithofallic,
Margaric, and Stearic.

4. Neutral Nitrogeiious Compounds : Creatine, Urea, -
Cystine, and Creatinine.

5. Neutral Non-Nitrogeiioiis Comj^ounds : Sugar from
the Liver, and Sugar of Milk.

6. Fatty and Saponaceous Compounds : Cholesterine,
Oleic Acid, Stearic Acid, Oleine, Stearine, &c. (13.)

7. Coagidahle Principles: Fibrine, Albumen, CaseinCj
Globuline, Musculine, Osteine, Keratine, Hematine, &3. (18.)

16. State the number nf these principles that "have Been alreaily found. What are
one half of them derived from? Giro the first group, or the gaseous ones. State th«
Salts. Tho Actds. Tbo 4th, 6th, 6th and 7tli clasees. . •

AT^-D PHYSIOLOGY.

IT. Immediate Principles Physiologically Grouped.—
If we group the preceding substances according to their phy-
siological relations, we might, with Dr. Carpenter, bring them
all into four divisions.

1. Hlstogenetic Substances^ or such as are converted into
animal substances, and are nitrogenous.

2. Calorific Substances, mainlj intended to produce heat,
and are non-nitrogenous, as, sugar and oils.

3. The co?npone?its of the living animal substance.

4. Excrementitiotis Substances, formed within the bodj,
and thrown out of it.

18. Other Probable Principles.— Quite a number of other
substances have been detected in the human sjstem, which
some regard as immediate principles. But it is safer to Avait
till further examination has removed doubt.

19. Several of the above principles are capable of crystal-
lization, and are some-
times found in that state
in the body. Figs. 1
and 2 show two exam-
ples of these crystals,
the first of Hippuric
acid, and the other of
Creatine.

20. To go into minute
details respecting the im-
mediate principles above
described, would occupy
too much space in a work
like the present. But a
few -statements^-respect-
ing the most import-

17. What are the Groups of these substances when physiologically grrouped ? Who \s
the authority for tl).is? Define the Ilistogenetic and the Calorific group. What are ex-
cremoatitjous eubstances? Are tbero any other principles in the body ?

1*

Fig. 1.

ro

HITCHCOCK'S ANATOMY

Fig. 2.

ant of them seem desir-
able.

21. Oxyjren.— Oxy-
gen is regarded as an
immediate principle only
when it exists in a free
state, as it does in the
blood, which, in an
adult, contains sixty-
one grains : nine and
a half cubic inches be-
ing found in the arte-
rial, and fourteen and a
half in the venous blood.
An adult consumes in a year about eight hundred pounds of
oxygen. An inhabitant of a mountainous region 18,000 feet
above the sea (in Potosi) consumes, however, only two thirds
as much as one upon the sea-shore.

22. Hydrogen ami Nitrogen. — Hydrogen is found in a free
state in the stomach and some parts of the intestines, and
nitrogen in the lungs, blood, and intestines.

23. Carbonic Acid. — Carbonic acid is found in the lungs,
the alimentary canal, the blood, and urine.

24. AVater; Cubical Size of the Body. — ^\\^ater enters into
the composition of every fluid, and every solid in the body.
The bulk of the body, upon an average, is equal to a cube of a
little more than sixteen inches on a side ; and the amount of
water equals a cube a little more than fourteen inches on a
side, or nearly three fourths of the body. Every part, ex-
cept bone, enamel, teeth, tendon, dry cuticle, and elastic tis-
sue, is more than half water.

21. TIow much 0.\-y_'cn by weight is found in the body ? What bulk of oxygen is found
In the venonsand what in the arterial blood ? How niuch does an adult consume by re-
sy»kfttior» nnd^thenviso in a ywir?- What effect does cleN-ation above the sea have upon
the amouiit consumed? 22. State how Ilydroiron and Nitrogen are found. 23. Carbonic
nrid also. 24 How important a constituent is water? Give the size of the body if re«
ducc'd to a cube. If this cube were water, bow large would it be ?

AND niYSIOLOGY. 11

25. Amount of Water Consumed Yearly by an Adult.—
An adult drinks about fifteen hundred pounds of water jearlj;
and throws off through the various waste-gates nineteen hun-
dred pounds. The difficulty of accounting for the four hun-
dred pounds has led some to suppose that water is formed in
the system by the union of oxygen and hydrogen.

26. Common Salt in the Body. — The salts that have been
enumerated, are found in almost every part of the body. Com-
mon salt (Chlorid of Sodium) is found in every fluid and solid,
except enamel. The whole amount in man i3 277 grains. It
subserves many important uses.

27. Carbonate and Phosphate of Lime, &;c. — Carbonate
of lime exists in considerable quantity in the bones, along
with a much larger quantity of the phosphate of lime, and a
small amount of phosphate of magnesia, and of fluoride of
calcium. These salts, except the fluoride, arc found in most
other parts of the body.

28. A c i d S , S a 1 1 s , & C . — Most of llic acids ai id salts, the neu-
tral nitrogenous compounds, the sugars, the fatty and sapona-
ceous compounds, exist, or are formed in the fluids of the
body, and though numerous (forty-two in all), their quantity
is comparatively small. They are mostly formed by disassimi-
lation in the body, and hence only their elements need to
exist in our food.

29. Sugar in the Body. — Only two kinds of sugar exist, or
are formed in animals. Grape sugar is found in the liver, in
some of the veins, and other organs. In the disease called
Diabetes, its quantity is very much increased, and, in fact, an
excess of sugar in the system is a sign of serious derangement.

30. Fats in the Body. — The fatty principles, cholesterine,
oleine, etc., exist in the body in cells, in chemical combina-

25. How much water docs a ihan consume in a year?" Ilmv much is thrown olTdurinj:
tho same time? Exphiin tho reason. 26. Where does commcn salt occur in the body ?
How many grains exist in the body? 27. lu what ]iarts of tho body do Carbonate and
Phospliate of Lime occur ? 2S. How many acids and salts are found? State how they
are formed. 29. How many kinds of sugar are found in animals ? What does au excess
of sugar indicate ? 30. How do the iats occur in the body ?

12 niTc II cock's a:!^ atomy

tion with other substances, and as oil drops or fat globules
not inclosed. These principles are mostly taken as food into
the system, but they are most probably also formed there
from elements ; certainly, the liver has this power. One
tenth of the brain is composed of fat ; and it is only in the
last stages of emaciation, that this supply is exhausted.

81. Assiniiiatioii Necessary. — The principles thus far de-
scribed, constitute but a small proportion of the animal frame.
But the organic, or coagulable principles, enter largely into
its composition. Indeed, they form the principal source of
nourishment. The most important of these principles (albu-
men, fibrine, and caseine) are in a fluid state in the body ;
tli3 others are solid, or demisolid. Though the materials for
their formation must exist in the food, yet there is reason to
suppose that the process of assimilation is necessary, to trans-
form them into these principles.

32. Albumen, All) u mi nose, Casciiir. — Coagulation takes
place when a liquid, or semi-liquid, passes into a solid state.
The white of an egg gives a good idea of one kind of albumen
(ovalbumen). Seralbumen exists in the blood, and in other
liquids of the body. Albuminose is found in the same fluids,
and has been, till of late, confounded with albumen. It is
formed in the upper intestines, but when it passes into the
blood, it becomes mostly albumen, sometimes musculine,
fibrine, etc. Animal caseine is found only in milk, being
most abundant when an animal diet is used. It contains from
four to six per cent, of phosphate of lime, and hence the im-
portance of milk for young animals, that their bones may l^e
developed.

83. FIbriiic, Musculine, Globulinc, Osteinc, and Gluten. —
Fibrine is found in the blood, and when it coagulates, the mass
ii fibrous, the process being called fibrillation. It is this prin-
ciple chiefly that causes blood to coagulate, the great importance

Is fat formed in the body, or takon in from the food? 81. State the throe most im-
portant orjranic principles. 32. Define coajiirlation. What is ovalbumin, seralbumen and
albuminose? In what is caseine foimd? What imi)ort*nt injiredicMit does it contain?
o8. Where is fibrine found ? What causes coagulation of the blcx>d ? What practica.1 b«*ne-,
fit is <lorivc<l froui coagulation ?

AND PHYSIOLOGY

13

Fig. 3.

of ^vliich in arresting dangerous hemorrhages is well known.
Coagulation appears to be a vital process, that is, dependent on
life for its development, and not on chemical laws only. It can
be prevented by any thing that destroys life, such as poisons,
or a temperature too high, or too low. Fibrine does not exist
in the muscles. That which has been called such is muscu-
line, which is endowed w^ith the vital property called contractil-
ity. Globuline occurs only in the red corpuscles of the blood.
Osteine is the substance from which gluten is made, by the
action of boiling water, for gluten does not naturally exist in
the body. Osteine is the essential organic element in bone.

34. He ma tine. — Hema-
tine is the coloring matter
of the blood, and though
iron is found in connec-
tion with it, all the iron
can be abstracted without
destroying the color.
Hence, that can not de-
pend on the iron. He-
matine is probably pro-
duced from certain red
crystals, occurring in the
red corpuscles. A group
of these crystals is here
shown.

35. Proteine Compounds. — All the organic or coagulable
principles contain nitrogen, or rather, are composed essen-
tially of oxygen, hydrogen, carbon and nitrogen. Hence, their
value as food, since a greater part of the body is composed of
these elements. Albumen, fibrine, and caseine have been
termed Proteine Compounds, for they can easily be changed

~Is fihTinefonnd in iniiscnlar tissue? Wliat is the proxinvate prineiplts of iniiscukir tis-
sno? Where does globuline and osteino occur ? 34. What is the coloring matter of the
Uood? Has iron any thinir to do '.vith its color? What is the Heniatine produced from ?
So. What foiir simple elements make up all tlio organic priaciples? Why are albumen,
etc, t<^rmod Proteine com jxwads? ......

n HITCHCOCK'S A X A T O :M Y

into Proteine, a substance, however, which does not exist in
nature, but results from the decomposition of the principles
above named.

HISTOLOGY.

36. Organic and Inorganic Structure. — Animals and
plants have a structure different from that of minerals when
we examine them with the microscope. The former is called
Organic, and the latter Inorganic Structure.

37. Vitality the Cause of Organization. — Vitality, or the
principle of life, or the Vital Force, is the cause of organi-
zation. The nature of life is indeed involved in obscurity ; but
its effects are manifest, and among them is organization : al-
though some have maintained, but without good reason, that
the vital force is nothing but a peculiar manifestation of heat,
mechanical force, chemical action, galvanism, etc.

38. Elementary and Primary Tissue. — The simplest forms
of organized structure are three.

1. Simple Membrane.

2. Simple Fiber.

3. Cells.

These organic forms physiologists denominate Elementary
Tissue. When united, they form Primary Tissue.

39. Histology; Proportion of Tissues in tlic Body. —
Histology is the science of Tissues. Tissue forms nearly the
whole of the solid portions of the body. By means of the mi-
croscope, they have been examined with great care, and de-
scribed.

40. Fluids of the System; Ilygrology. — Before entering
upon a description of the tissues, it seems desirable, at least,
to enumerate the different fluids found in the system, though a

of!. Define organic and inorsranic structure. 37. Give the cause of organization.
PS. Stato the three simple forms of organized structure. What is Elementary Tissue?
What is Primary Tissue? 89. Defiae Histology. What forms tbo solid j^arts of the
body ? 4a Wliat b Ilygrology ?

AND PHYSIOLOGY. 15

fuller description of them will be given further on. These
fluids contain the elements of the tissues. That part of
anatomy which treats of them is called Hygrologj.

41. Lynipli. — Lymph, a transparent, coagulable fluid, in
the lymphatics, emptying into the blood.

42. Chyle. — Chyle, a white, coagulable fluid, derived from
the food in the intestines, and conveyed to the blood.

43. Blood. — Blood, in the veins and arteries, from which
nearly all the parts of the system are sustained, a coagulable
fluid, with an alkaline reaction.

44. Serum. — Serous secretions, fluids found on various
serous membranes, as the pleura, peritonaeum, pericardium,
and membranes of the brain and ear.

45. Transudations. — Transudations, vapor from the lungs,
and sometimes from the skin ; also, fluids in some of the tis-
sues, more especially in certain diseases, as dropsy in the
head, chest, and abdomen, certain sweats and discharges in
cholera, etc.

46. Exudations. — Exudations, ''any organizable fluid
spontaneously separated from the blood vessels, without rupt-
ure of their walls," chiefly occurring in inflammations, and
wherever new material is required for repair of the system.
The pus of wounds and sores is an example of exudation.

47. Mucus. — Mucus, a viscid mass capable of being drawn
into threads, secreted from the mucous membrane, but difier-
ing in different parts. •

48. Gastric Juice and Pepsin. — Gastric fluid, a fluid
cecre ted by the stomach, containing a substance called Pepsin,
which aids in digestion. It contains a little free chlorohydric
and lactic acids.

41. What 13 Lymph and what becomes of it? 42. Define Chyle and state what bo-
comes of it. 43. Define the blood. 44. What membranes secrete the serum ' 45. Define
transudations. In what diseases do they occur ? 46. What arc exudations ? AVhen aro
they serviceable ? 47. What does the mucous membrane secrete ? 4S. Define and de«
ecribe the secretions of the stomach.

16

HITCHCOCK'S ANATOMY

•C O'VvO'

'' -" ° "'^ ^a'oSif

O V„"0

O oOOO,

1^ ■=4' «*'o7-r^ " oa>-'w»'

yao

o OoO o

O^

pc
o oo:^t^ C

o„ or

r

49. Intestinal Fluid.— The intestinal fluid, a colorless,
tenacious fluid, with strong alkaline reaction, whose function
is to assist in digestion. Secreted hj the epithelial cells of
the intestinal follicles.

50. Milk.— Milk, a
glandular secretion,
showing under the mi-
croscope an immense
number of fat globules,
suspended in a clear
fluid, as in fig. 4.

51. Saliva, — Saliva,
a secretion chiefly from
the parotid and submax-
illary gland into the
mouth, to assist in diges-
tion.

oTo^c^vgSiooO-"^ ^2. Bile.— Bile, a

greenish or brownish
bitter fluid, secreted by the liver to assist in digestion.

53. Pancreatic Juice.— Pancreatic fluid, a colorless, taste-
less, but somewhat alkaline fluid, secreted by the pancreas to
aid in digestion.

54. Urine. — Urine, secreted by the kidneys.

55. Tears. — Lachrymal fluid for lubricating the eyeballs,
secreted by the lachrymal gland.

5Q. Oil and Wax. — Sebaceous secretions, fatty fluids thrown
out by what are called the sebaceous follicles of the skin, to
keep it moist. '

57. Sweat. — Perspiration, or sweat, a colorless, watery

49. What is the Intestinal fluid ? 5i). How does milk appear under the microscope ?
.^l. What is the origin and use of saliva? 52. State the secretion of the liver. 58. &c.
Describe Pancreatic Juice. Urine. Tears. Oil and Wax. 57. From what glands is
sweat produced ?

AND PHYSIOLOGY. 17

fluid, with a saltish taste, and having odor, secreted from the
perspiratory glands.

Elementary Tissues.

58. Simple, or Basement Membrane. — 1. Sifiiple Mem-
brane. This is usually a structureless layer of coagulated
albumen, often not more than 20000th of an inch thick. It
forms the walls of all cells, and is also spread out, as an in-
ferior layer of the skin and mucous membrane, and is then
called basement membrane. It is the most simple of all the
tissues, yet it is the agent of secretion, and sometimes of ab-
sorption, and these Professor Peaslee considers as its vital
properties, though of a low grade.

59. Imbibition. — Simple membrane also possesses the re-
markable property of allowing fluids to pass through it when
it is placed between two fluids ; the efiect depending in part
upon the electro-chemical relations of the substances, but not,
as generally supposed, on the difference of specific gravity
of the liquids. This is called endosmose and exosmose, or
Imbibition, and is the principal means by which fluids are
made to pass from one part of the system to another, where
no distinct vessels are provided far that purpose.

60. Simple Fiber, — 2. Simple Fiber. This consists es-
sentially of threads of coagulated

fibrine, whose average diameter is
about 8 -'0 oth of an inch thick. It
does not appear to be a permanent
constituent of the body, but only
a basis for the development of the
more complicated tissues. A good
example of the simple fiber may
be seen in the membrane lining
the inside of an egg shell, as in
Fig. 5. ^

58. What is slmpla membrane ? How thick ? Where is it found ? What other name
is given to it? 59. Describe Imbibition. What purpose does it effect? 60. Descfibo
•imple fiber. Its size. Where best sc en ?

18

HITCHCOCK'S ANAl O M Y

61. Shape of Cells.— 3. Cells. These aie merely mem-
branous-Jbags, or vesicles, from , ioth to b^'ooth of an mch in
diameter, filled with some kind of liquid, or solid substance.
When free, the form is spherical, or spheroidal, as m Fig. 6.
But, as they press against one another, they are brought into
a polyhedral form, as in Fig. 7, showing a group of fat ve-
sicles.

Fig. 6.

Fig. n.

62. Contents of Cells; Granules; Nucleus and Nucleo-
lus.— The fluid of cells is transparent, except in the case of
blood. In it there generally float an immense number of gra-
nules, having no investing membrane, but sometimes they are
thus invested. Each cell has also a nucleus and a nucleolus ;
the first being a globular, or lenticular body, from ^ o'o oth to
eo'ooth of an inch in diameter, attached to, or imbedded in the
wall of the cell, though some are free. The nucleolus is a
granule within the nucleus. Both are shown, as well as the
common granules, in Fig. 6.

63. Appendages of Cells. — Sometimes cells have a sort o?
tail attached to them, and are hence called caudate, as in
Fig. 8. Sometimes, too, they are stellate, as in Fig. 9, show-
ing the pigment cells of a frog's foot.

Cl. Define cells. What is tho original form of theiii? How do they .icq;;iro the poly-
hedral form? C2. Explain nucleus, nucleolus and cell wall. 63. What are the appendages
of cells ?

and physiology.

Fig 8.

19

FiQ. 9.

64. Cytogenesis. — The cell is the most important of the ele-
mentary tissues, for, by its multiplication, mo^^t of the other

64. Give the process by which cells increase and form tissuet

£0

HITC IT cock's ANATO:\rY

Fig. 10.

tissues in animals and vegetables are made up. This is called
cjtogenesis. The increase usually takes place by duplicative
subdivision, which is shown on Fig. 10. The cell a a first
becomes elongated, as at &, and then it divides at c c. The
subdivision going on will give an increase in lapid ratio — 2,
4, 8, 16, 32, etc. Fig. 11 shows an example of this division,

A, B, C, D, in its earlier
stages, and E, F, G, H, in
its more advanced condition.
Sometimes cells multiply by
the development of new cells
in the interior In this case
the nucleus subdivides into
two or more portions, which
at length fill the original cell,
as is shown in Fig. 12. Some-
times cells are formed by the
expansion of homogeneous"

9i):

mm

Fig. 11.

B 0

P

vr

granules into cells ; or they are even produced in the midst of
a formative fluid (called a blastema), poured out from the blood.

Doecrlbe the roodo of fornrntioo as lUustratod lo Figures 11 and 12. What U tb«

AND r I! Y S 1 O L O G T .

21

Fig. 12.

65. It is in these
ways that most of the
tissues of the body are
built up, and the animal
enlarges to its full size.
It has been maintained
that all the tissues orig-
inate in cell develop-
ment. But, m some
cases, simple fibers and
membranes seem to be
formed directly out of
an organizable s u b -
stance, without the in-
tervention of cells.

QQ. Vital Force of
Cells; Chemical Trans-
formations; Vitalization of the Cells; Change of Form;
Development of Nerve Force.— The multiplication of cells
is one of the manifestations of the vital force inherent in them.
Another is the chemical transformations exerted upon the con-
tents of the cell in some instances, whereby new products
are generated. Another is the vitalization of a portion of
the cell contents, whereby they are able to produce new
cells. Another is permanent changes of form in connection
with growth. Another is temporary changes of form, ac-
companied with sensible motion, as in the oscillatory move-
ments of the leaves of Hedysarum gyrans, and th-e fold-
ing of the leaves of the Mimosas upon touch. Finally, the
development of nerve force from cells, by which all the bodily
operations may be modified, and which is intimately connected
with mental agency.

67. Periods in the Life of the Cells. — In cell life there is a

' 65. Show how the tissues of th« body are moda tip. 66. Meotion the different cluosos
which cells anderso.

22 II I T C 11 C O C K ' S ANATOMY

period of augmentation, another of perfection, another of de-
cline, and, finally, one of cessation. So long as vitality can use
chemical and physical agencies for building up the system,
they tend to its preservation, but, when life ceases, they tend
to its destruction, not, as is generally thought, because the
vital principle has not the power of resisting these agencies,
but because it can no longer turn them into the channel for pre-
serving the system.

PRIMARY TISSUES.

The chief mass of the animal system is made up of the ele-
mentary forms that have been described, variously combined
so as to form plexuses and webs^ which are called primary
tissues by some, and compound tissues by others. They are
differently classified by different writers. The arrangement
which follows is that of Professor W. B. Carpenter :

1. Simple Fibrous Tissues.

68. White and Yellow Fibrous Tissues.— This embraces
the white and yellow fibrous tissues, as well as the areolar or
connective tissue of other writers. The white fibers are from
isVooth to the oooooth of an inch in diameter, and form the
tendons, ligaments, and fibrous membranes. (Fig. 13.) The

Fia 13

Fig. U

67. Give the four different periods in the life of cells. 6S. Give the size of the libera
of white and yellow fibrous tissues.

AND PHYSIOLOGY.

23

yellow fibers are about 73^0 otb of an inch in diameter and form
a part of the larynx, and the middle coat of the arteries.

69. Areolar Tissue. — The areolar tissue consists of fibers
of white and yellow tissue interwoven, so as to leave irregular
spaces, or areolae, between them. This tissue originates from
cells, as is shown in Fig. 16. The areolar tissue is more widely
diffused than any other in the body, so that if it were possi-
ble to remove all but this one, the form of the part would be
preserved. It surrounds all the arteries and veins, the nerves,
muscles and internal organs ; and it forms one of the layers of
the skin and mucous membrane.

Fig 15.

FfG. 16.

2. The Fibro-Cellular Membranes.

70. One of the layers of the skin, of the mucous membrane,
and the serous and synovial coat that lines the shut cavities of
the body, is composed of interwoven fibers of simple basement
membrane , and of one or more layers of cells upon the free

69. What is the composition of areolar tls.sue? What of its abundance In the body!
Whore Is It principally found ? 70. Describe the fibro-celliilar jnembrane.

2

24

II I T C H C O C K ' S .V N' A T O il Y

surface. This is the fibro-cellukr membrane or tissue. Its
position and character will be better understood when the parts
above referred to have been described in subsequent sections.

Fig. 17.

Fig. 38.

8. Cellular Tiss^ues.

71. Fat and Cjirtilage. — These embrace the adipose tis-
sues, Fig. 17, and the cartilaginous, Fig. 18. The first is the
usual form of fat, wherever it occurs in the system. It retains
the pure form of the primitive cells. In cartilage, also, these
cells sometimes exist alone, but more frequently they are inter-
woven with fibers, as seen by the figures.

4. Sclerous Tissues.

72. Bones and Teeth.— These constitute the bones and
teeth, and are composed of an animal basis of fibers and cells ce-
mented together by phosphate and carbonate of lime. Fig. 19,
which is a transverse section of one of the bones of the arm,
will give an idea of the arrangement of the animal matter,
the earthy part having been dissolved by acid. Fig. 20 shows
a transverse section of the shoulder blade, exhibiting the dark
spaces called lacunas.

71. Describe fat and cirtilage. T'i. What 13 the coinpositioa of the bones and th»
teeth ? 73. Wh;it are the cajullaries ami absorbents ? Give tho size of the capillarlos.

and physiology.

Fig. 19.

25

TuBULAK Tissues.

73. Capillaries and
Absorbents. — These
form those minute blood
vessels called capillaries,
and others called lym-
phatics or absorbent ves-
sels, which exist m every
part of the body, and
are distinct from, al-
though connected with,
the arteries and veins.
The capillaries c o n -
necting these are from

so^oth to ai'oith of

Fig 20

58

Hitchcock's anatomy

Fig. 21.

an incli in diameter, less often than the blood cor-
puscles. In some other animals thej are larger,
as may be seen in the capillary plexus of a frog's
foot, shown in Fig. 9. The lymphatics abound
with valves, ds may be seen in Fig. 21.

6. Muscular Tissue.

74. Striped and SKiooth Muscle. — This tissue

is made up of two forms of fiber, the striped and

nnstriped. The stripes in the first form run both

transversely and longitudinally, as may be seen

Fig. 22.

Fig. 23.

w

m
m
m
m
m
m
■

I
1

1
1
1
1
1
1
1

in Fig. 22. When separated loQgitudinally, the
fibrillae have a beaded appearance, each bead
being in fact a cell, as is here represented in
Fig 23, which shews the cells a when most
relaxed, and b when most contracted. Muscular
fiber is capable also of being divided crosswise
in the direction of the transverse striae into discs,
as seen in Fig. 24. Both the striated (striped)
and non-striated muscles originate in cells.
Figs. 25 and 26 show their development.

75. Myotility. — The grand peculiarity of
muscular tissue is its power of contraction — a
phenomenon as mysterious and wonderful as
any thing in nature. This is called myotility
or contractility.

What do the lymphatics abound in ? 74. Distinguish between the strii)ed and the
nnstriped muscular fiber. Give the reason of the difference between a .lud & iu Fig. 23.
15. Define inyctillty.

AND PHYSIOLOGY

Fig 24.

Fig. 25.

Fig. 26.

76. The Chemical Composition of Muscle. — The chem-
ical composition of the muscular tissue is almost exactly the
same as that of blood, as the following analysis will show :

Blood.

Carbon 51.83

Hydrogen I.Ql

ITitrogen 15,01

Oxygen 21.36

Ashes 4.23

100.00

Muscle.
51.95

1.11
15.07
21.39

4.52

100.00

76. state the chemical corapositioii of muscle.

■2$

HITCHCOCK'S ANATOMY

7. Nervous Tissue.

77. NcFTOUS Tissue; Tubular Cells. — This, like some of
the other tissues, is composed of cells, fibers and tubes, but it is
distinguished from all others by its vital endowments. In the
ordinary nerve trunks the tissue is the fibrous or tubular, as is
shown in fig. 27, A, B, and C. In C some of the original cells
are shown.

Pig. 27.

78. Vesi- Fig. 28.

cular Cells;
Granular
Cells.— -In
those nervous
masses called
ganglia, w e
find, in addi-
tion to the
fibers, a sub-
stance made
up of vesicles
or cells, as is
shown in the ganglion of a mouse on fig. 28.

77. Tlow is nervous tissue to be distinguished from all other tissues? 78. Describe
the vesicular cells.

AND PHYSIOLOGY. 29

Another primary element of the nervous system is com-
posed of nucleated cells, containing a finely granulated sub-
stance. These sometimes have processes -which give them a
caudate or stellate form, as in Fig. 29.

Fig.. 29.

79. All Organ. The System.— Such are the tissues which^
combined in various proportions, make up the organs of the
human body. And by the term organ we mean a part usually
composed of several tissues adapted to certain functions. And
though harmoniously united into a single system, that is, the
body, the anatomist can dissect and describe them separately.
In this work the following order will be adopted :

1. Osteology^ or an account of the Bones or framework of
the system.

2. Myology^ an account of the Muscles or the moving pow-
ers of the system.

3. Splanchnology^ or the Nutritive Organs.

4. Angiology^ an account of the Circulating System of the
arteries and veins.

Tf , Define an organ. What is the sfstem ? What is Osteology ? Myology ? etc.

30 HITCHCOCK'S ANATOMY

5. Pneumonology^ or an account of the Respiratory, Vocal,
and Calorific Organs.

6. Ichor ology^ or the Lymphatic and Secreting System.

7. Neurology^ or the history of the Nervous System, the
vivifying power.

8. The Inlets of the soul, or the Senses.

9. Religious teachings of the subject.

CHAPTER FIRST.

THE FRA^IEWORK OF THE SYSTEM.— OSTEOLOGY, OR
A DESCRIPTION OF THE BONES.

DEFINITIONS AND DESCRIPTIONS.

80. Chemical Composition of Bone. — The Bones of all
vertebrate animals are principally composed of the Phosphate
and Carbonate of Lime, and, with the exception of the Teeth
and articular extremities, are closely covered by a firm mem-
brane called the Periosteum. By chemical analysis the com-
position is as follows :

Organic substance (Osteine or Cartilage) 33.00

Phosphate of Lime 57.00

Carbonate of Lime , 8.00

Fluorid of Calcium 1.00

Phosphate of Magnesia 1.00

100.00

81. Cartilage and Salts of Lime shown. — Hence we see
that the principal constituents of bone are the salts of Lime
and Cartilage. The former can be easily obtained by burning
the bone a while in a hot fire, which appears like a white
powder when crushed. The Cartilage is obtained by im-
mersing it for a considerable time in a dilute acid, when we
have the form of the bone perfectly retained, although nothing
is left but cartilage. Its elastic character may be inferred

80. What are the principal ingredients of bones? Where is the Periosteam found?
Give the chemical analysis. 81. How can the earthy ingredients be shown ? The car-

32 HITCHCOCK'S ANATOMY

^iG. 30. from Fig. 30, "which is a human

Fibula tied in a knot after hav-
ing been immersed for some
time in muriatic acid.
wjii^^^MS 82. Mechanical Construc-

tion of Bones. — As a general
^^^^^___ _ laTV the extremities are the

^ ^^^^^^^m. largest, and the bodies or shafts

.^^^^^^^^^. ^^^ smooth and of a uniform

surface. Thej are in most
V'^^^lll^llllillililil^^ cases so constructed as to give
^^^^^^^^m the greatest strength and sup-
port, and at the same time fur-
nish as little weight as possible.
Hence the long bones are most-
ly hollow, or have an arched
form, while the flat bones are
portions of a circle or sphere. In the face also the bones are
not all solid, but some of them contain large cavities, so that
firm attachment maj be given to the muscles, and protection
to the more delicate parts.

83. Average Weight of adult Skeleton.— The weight of
the skeleton is as 10.5 : 100, or about one tenth the weight
of the whole body. And since the average weight of an adult
man is 136 pounds, the weight of an adult skeleton is about
13.5 pounds.

84. Strength of Bones — The power of the human bones
as levers when compared with different substances is remark-
able, as is seen by the following table.

Freestone (sandstone) 1.

Lead 6.5

Elm and Ash (wood) 8.5

Box, Tew, and Oak 11.

Human Bone. 22.

82. Which part of the bones is generally the largest? Why are many of the bones
hollow or partially so? 88. Give the weight of the human skeleton. What is its pro-
portion to that of the whole body ? 84 Give the comparative strength of the bones.

AND PHYSIOLOGY.

33

That is, bone when used as a lever is 22 times as strong as
Sandstone, 3^ times as strong as Lead, nearly 2^ times as
strong as Elm and Ash, and 2 times as strong as Box, Yew,
and Oak timber.

85. Microscopic Structure of Bone. i'ig- si.
Haversian Canals. — Examined by
the microscope the bones are found to
be made up of plates or layers for
the most part, arranged concentrically
in the long bones, and in parallel
layers in the flat ones. These are
traversed in all directions, and espe-
cially in their long diameters, by
minute tubes or vessels called Ha-
versian canals, which are also en-
circled by several laminae or plates
besides those following the general
outline of the bone. Fig. 31. These
canals have a diameter varying from
T2V0 to 04 o^li of an inch, while the
accompanying lamellae show a thick-
ness of eoVoth of an inch. They
sometimes contain a capillary vessel,

but more usually carry only the nutritive and watery portion
of the blood.

86. LacunsB, Canaliculi. — Besides these canals we find a
smaller set of vessels or cells located directly in the substance
of the concentric lamellae, called Lacunae or Bone Corpuscles,
which average yoVoth of an inch in length, and carry the fluid
which nourisbes the bone. These are of a black appearance,
of an oval form, and with rays divergent in all directions, as

TransversG section of bone
magnified 15 diiinicters. 1, Outer
layer. 2 and 3, inner layers.

6d-.- How-are tbe- particles of matter arranged in the long bones ? How in tbo flat
ones? Describe the Haversian canals. Their diameter. What vessel does each one
contain and what is the purpose of that vessel? 86. What are the LacunjB or Bono
Corpuscles?

34

HITCHCOCK'S ANATOMY

LacuniB of Bone, a, central portion.
&, canaliculi or Bone Pores.

87. Ultimate Graniiles.-

FiG. 33.

^M

Fig. 32. seen in Fig. 82. These

rays are minute canals,
and nearly all of them
anastomose, or have com-
munication with each other.
They are called Canaliculi,
or Bone Pores, and mea-
sure sooooth of an inch
in diameter.

The ultimate histological ele-
ment, or the smallest element of bones as yet
discovered, is made up of pale oval granules,
about e^oVoth of an inch in diameter. These
granules constitute all the substance of the bone
except the minute vessels already mentioned.

88. Hence the microscopic elements of bone are four :

1. Haversian Canals.

2. Lacuna or Bone Corpuscles.

3. Canaliculi or Bone Pores.

4. Ultimate Granules.

89. Periosteum. — In all parts of the body, both solid and
fluid, we find that nature has made ample protection by
providing for nearly every organ a firm membranous sheath.
This not only serves as a protection and support, but in
many cases a means of nutriment. Upon the bones ac-
cordingly we find a very firm whitish yellow membrane
closely attached to them in most places, and very smooth,
called the Periosteum. This occurs on every part of every
bone, except at the articulations, and upon the crowns of the
teeth. It is, when healthy, perfectly insensible, and contains
the vessels which ramify into the bones, being in fact the

What are the Bone Pores or Canaliculi? 87. What is the smallest or nltimate element
of bones ? 88. Give the four microscopic elements of bone. 89. What is the color of
the Periosteum? On what part of the t)oaes is it wanting? What two Important
purposes does it subserve ?

AND PHYSIOLOGY.

35

nutrient membrane of the bones. Besides ^i^- 34.
this function, the periosteum serves as a
point of attachment for the ligaments and
tendons, in as much as they could not find
firm attachments on the bone itself.

Remark. — Diseases of Periosteum. — In
the diseases known as Felon and Fever Sore,
the Periosteum is the seat of the inflamma-
tion, although, if it be not soon checked, the
bone itself becomes implicated.

90. Processes of Bones. — The bones of
animals are not constructed after any regu-
lar geometrical form or curve, but are mod-
eled upon the plan which may secure the

» 1 r -T ^ • Periosteum of a liumo-

greatest firmness and lacility oi motion, rus partly taken off.
Accordingly we find their surfaces quite
uneven, presenting in many places prominent projections,
which serve as a firm point of attachment for muscles and
ligaments. These are called Processes, and are generally
found near the extremities of bones, and are largest where
the greatest strength of muscle and ligament is required, as
shown in the bones of the lower extremities.

91. Nutritious Foramina. — Upon nearly all the bones of
the body may be found small tubular openings w^hich, after
extending for a short distance into the bone, ramify and give
off the minute capillary vessels which circulate through the
larger Haversian canals. They are called nutritious fora-
mina, or openings, since they convey nutriment to a large
portion of the bone.

92. Four Classes of Bones. — Bones are divided according
to their shape into four classes : long, flat, short, and irregu-

What is the seat of Felon and Fever Sore? 90, What is the general outline of bones?
What are Processes? 91. What are the nutritious foramina, and with what vessels do
they communicate ? Their uso ? 92. Give the four classes of bones, and give examples
of the long ones. ^

36 HITCHCOCK'S ANATOMY

kr. The long ones are mostly found in the extremities, and
consist of a hollow shaft with enlarged and partially smoothed
extremities, and sometimes a rough or elevated portion along
their central portions. Those which belong to this class, are
the Clavicle, Humerus, Radius, Ulna, Femur, Tibia, Meta-
tarsus, and Metacarpus, Phalanges and Ribs.

93. Short Bones. — The Short bones are irregularly cuboid
in form, and are found in those places where there is but
little motion of the part. They are the YertebrsD, Coccyx,
Carpus and Tarsus, Patella, and Sesamoid bones.

94. Flat Bones. — The Flat bones are arranged to enclose
and protect cavities. Those of the head are made of two
layers of bony matter, with an intervening porous substance
called the Diploe. These are the Occipital, Parietal, Frontal,
Nasal, Lachrymal, Vomer, Sternum, Scapula, and the Os
Innominatum.

95. Irregular Bones. — The Irregular bones are those
which belong to neither of the pjreceding classes, and have
no typical form. They are the Temporal, Sphenoid, Eth-
moid, Superior and Inferior Maxillary, Palate, Turbinated,
Hyoid, and Sacrum.

96. Development of Bone from Cartilage. — The early
condition of bone is that of cartilage, which has the general
outline of the bone, and from the subsequent process may
be called the mould of the bone. Very early in life, and
even before birth, bony matter begins to be deposited in the
cells of the matrix (cartilage) until at length, the whole
becomes solid, as it is found in adults. At birth the only
bone which is completely ossified is that portix)n of the tem-
poral called the petrous, which contains the organ of hear-
ing, while all the bones are not completely ossified be-
fore the 12th year of life. This process of hardening, or os-

93. What is the general outline of short bones and where are they found? Give es-
amjAes. 94. Give the use of the flat bones. Examples also. 95. What are some of
tlie-irregular bones? 96. What is the first stage of bone? When is the process of ossifi-
cation complete ? What boucs are the first that become ossified?

AND PHYSIOLOGT.

37

sification, begins at
certain points, and
continues until the
whole is completed
as is seen in the
Eig, 36. In some of
these bones there is
but one of these
centers, or points,
where ossification
commences, while in
the Sphenoid there
are 12.

97. Number of
Bones. — The num-
ber of bones in the
human system is
reckoned differently
by different anatom-
ists since many of
the bones are well
exhibited only in
hard working or
well developed mus-
cular subjects. The
number 246 will be
given in this book
as taken from Eras-
mus Wilson, whose
work on Anatomy is
adopted as the text

Fig. 35.

Section of cartilage near the point of ossification.
1, ordinary appearance of cartilage. 2 and 3, more ad-
vanced stages of ossification. 1', 2' and 3' portions
1, 2 and 3 more highly magnified.

book in nearly all the medical schools of this country. This in-
cludes the teeth, and sesamoid bones, of which the latter areiiot
constant in every individual. They are summed up as follows :

9". What is the number of bones in the human body? Give the dififcrent gi-oups.

88 HITCHCOCK'S ANATOMY

Fig. 36. Fig. 37.

mm

A knee joint showing points of ossification,
1, 2 and 3.

Head S

Ear 6

Face U

Teeth 32

Vertebrae, Sacrum and Coccyx 26

Os Hyoides, Sternum and Ribs 26

Upper Extremities 64

Lower Extremities 62

Sesamoid Bones 8

246.

98. VertebrsB, Groups of Verte-
bra, Cervical Vertebrse. — The Ver-
tebrae or Spinal Column claim the
first attention, since they are the

Description of Fig. 87. Lateral view of the Spinal
Column. 1, Atlas. 2, Axis (second Vertebra.) 3, Last
Cervical Vertebra. 4, Liist Dorsal Vertebra. 5, Last
Lumbar. 6 and 7 Sacrum. 8, Coccyx. 9, a Spinouis
Process. 10, Intervertebral Foramina.

AND PHYSIOLOGY

39

Frontal Bone. FlG, 38. Parietal Bon«.
\ — /

Crblt —

Lower Jaw. — -

Cervical Vertebrae. --
Shoulder Blade.

Tibia.
Fibula.

TT?,im, , .

W /^

Ulna. /

Eadiu3. 1

1 m

Carpus. "Ja

Metacarpus. — --^|

1 1^

Phalanges. = — 'SM

1 l\

Femur. — .

11

Temporal Bone.

Clavicle.

__ Ilium.

- Patella.

,, Tarsus,
,. Metatarsus.
., Phalanges.

40

H I T C II C O C K ' S A X A T O M Y

first developed bones, and the center around "which the others
are formed. Thej may be separated into the true and false :
or those which are separable from, and movable upon each
other, and those which are firmly joined together. Of the
true vertebras there are three sections, named in accordance
with their location on the body : Cervical, Dorsal, and Lum-
bar. The Cervical, or those of the neck, are seven in number,
the first and second of which are the most remarkable. The
first is named Atlas, from the mythological story that a giant
of this name supported the earth on his shoulders, and it is

Fig. 39.

Fig. 40.

The Atlas. 1, Anterior Tubercle. 2, Articular
Face. 8, Posterior surface of Spinal Canal. 4, In-
tervertebral Notch. 5, Transverse process. 6, Fo-
ramen for Artery. 7, Superior oblique process.
8, Tubercle for transverse Ligament.

The Axis. 1, Body. 2, Proces-
sus dentatus. 8, Articulating sur-
face. 4, Foramen for vertebral
Artery. 5, Spinous process. 6 and
7, Oblique processes.

upon this one that the head is moved in a direction backwards
and forwards. The second, called Axis, is characterized by
a projection or pivot, which admits motion of the head in
a horizontal direction, but in no other. It is the dislocation
of this process, and the consequent pressure upon the spinal
cord that causes death in criminals executed by hanging.

99. Dorsal VertebrsB. — The Dorsal Vertebras, or those of
the back, are twelve in number, and give attachments to all
the ribs. The central portion or body of each increases from
above downwards, that they may more firmly support the
superincumbent weight of the body.

93. Why are the Vertebrae first described ? What two groups may they be divided
Into? What other three sections of Vertebra}? What is the name of the first and
Becond Vertebra ? 97. How many Dorsal vertebrae, and what bones are attached to
them ?

AND PHYSIOLOGY.

41

Fig. 41.

Fig. 42.

A Dorsal Vertebra. 1, The Body. 2 and The Sacrum. 1 and 2, Articular sur-

7, Faces for head and tubercle of Rib. 8, faces. 8, Promontory of the Sacrum. 4

Upper face of the body. 4 and 5, Interver- and 10, Lines of former division of Sa-

tebral Notch. 6, Spinous process. 8 and crum. 5 and 6, Foramina. 7, Sacro Ischia-

9, Oblique processes. tic Notch. 8, Ahe of the Sacrum. 9, Ob-

lique processes.

100. Lumbar Vertebrse. — The vertebras of the Loins, or
the Lumbar, are five in number, and are the largest members
of the spinal column, since they are the only bones in this
part of the body. They are more massive and solid in all
their parts than the rest of this column, that they may be
equal to the strength required of them.

101. Sacrum. — The Sacrum is a single bone, although
its typical form is that of five vertebrae, which are actually
found in some animals. Its appearance is that of five verte-
brae, which are partially anchylosed or grown together. The
form of the bone is somewhat like a wedge, with the base
directed upwards, and the point curving inwards and for-

wards.

102. Coccyx. — The Coccyx is the lower
extremity of the Spinal Column, formed
of four anchylosed and imperfect verte-
brae ; and it is an extension of these bones
in the monkey which makes the tail.

Fig. 43.

The Coccyx. 1, First bone.
2, 3, Processes to join the
Sacrum. 4 and 5, Notches to form Foramen. 6, Last bone.

100. How many Lumbar VertebriE? Why are they the largest in size ? 101. Describe the
Sacrum. How many rudimentary vertebrai does it consist of? Iu2. Describe the Coccyx.

42 HITCHCOCK'S ANATOMY

103. General Remarks on the Spinal Column. — The

Spinal Column viewed as a whole may be considered as
made up of four cones, owing to the different sizes of the ver-
tebrae. The apex of the upper one commences with the Atlas
and extends as far as the ^ first dorsal vertebra. Here the
second one commences in an inverted position, extending over
the upper three dorsal vertebrae. The third reaches with its
base as far as the top of the Sacrum, where the inverted
fourth one terminates with the Coccyx. Viewed from the
front the spinal column should be in a straight line when in a
healthy condition ; but a lateral view shows two curves, one
at the lower part of the neck, and the other at the lumbar
vertebrae, the design of this curvature being to place the
head and its delicate contents upon an elastic and flexible
support, and the design of the straight position in the other
direction, being to give equal tension to the muscles on both
sides.

104. Intervertebral Cartilage. — Between all the vertebras
is placed a thick cushion of cartilage. This by yielding not
only allows a free and ready motion to the column as a whole,
but is an additional protection to the brain, by diminishing
the severity of any vibration communicated from below.

105. Bones of the Head. — The Skull may be considered
as the superior expansion of the spinal column, when it — the
spinal column — is taken as the center of development of the
whole body, which contains in the cranium the brain, and in
the face most of the organs of sense.

106. In the Cranium or true skull are eight bones:

1 Frontal, 2 Temporal, 2 Parietal,

1 Occipital, 1 Sphenoid, 1 Ethmoid.

103. Of how many cones may the Spinal Column bo considered as composed? From
what direction does the Spinal Column appear in a straight line? What curvatures does
a lateral view show ? 104. What substance do we find between the vertebrse? Give
Its use. 105. What may the Skull bo considered as? What organs does it contain?
106. Give the bones of the Skull.

AXD PHYSIOLOGY

43

107. Frontal,
Temporal, Parie-
tal, Occipital,
Spfienoid,and Eth-
moid Bones. — The
rrontal Bone is sit-
uated in the upper
and front part of
the head, occupy-
ing that portion of
the skull called the
forehead. It is
mainly a flat bone,
but the portion
lying above the eye
is hollow, in order
that protection may
be afforded to this
delicate organ, as
well as to give sufficient
prominence to the up-
per part of the face.
The two Temporal Bones
cover the front part of
each side of the skull
in that position com-
monly known as the
temples, and each bone
is a little larger than
the space which is pro-
tected by the external
ear. In the inner por-
tions, called the petrous,
are located the organs

Fig. 44.

1, Frontal, 2, Parietal. 8, OccipitaL 4, Temporal.
6, Nasal. 6, Malar. 7, Upper Jaw. 8, Lachr7mal,
9, Mandible.

Fig. 45.

Frontal Bone. 1, Frontal Protuberance of riglit
side. 2, Superciliary ridge. 3, Superorbitary
ridge. 4 and 5, Angular processes.

107. What kind of a bone is the Frontal ? Why is a portion of it hollow ? W here are
the Temporal Bones located i

44

HITCHCOCK'S ANATOMY

Left Temporal Bone. 1, Squamous portion.
2, Mastoid portion. 8, Petrous portion. 4, Zygo-
matic portion. 5, Articulating surface for lower
jaw. 6, Temporal ridge. 7, Glenoid fissure. 8,
Mastoid foramen. 9, Canal for ear. 10, Groove
for digastric muscle. 11, Styloid process. 12, Va-
ginal process. 13, Glenoid Foramen. 14, Groove
for Eustachian tube.

Fig. 47.

^^^•^^- of hearing. Directly

behind the external ear
is felt a hard projection
wMch is the mastoid
process of this bone,
and serves for the
attachment of many
muscles, which move
the head. And directly
in front of the ear is
another prominent pro-
cess, called the zygo-
matic, which articulates
with the malar bone,
and to which is at-
tached one of the ele-
vator muscles of the
jaw. The two Parie-
tal Bones are eminently
flat bones of a square
shape, forming the es-
sential parts of the pro-
jections on the back
sides of the head, and
uniting; with each other
on the median line, up-
on the top of the skull.
They join with the
frontal bone in front, the
temporal bones below,
and the occipital bone
behind. The Occipital
Bone has an imperfectly circular outline, and at its lower

What i.s the mastoid process ? Where is the zygomatic process ? Give the form of
the Parietals. What is tbe outline of the Occipital Bone ? What is the large orifice la
Its lower part for? Give the position and general outline of the Sphenoid Bone. With
■what bones does this articulate ?

Left Parietal Bone. 1, 2. 3, 4, Superior, Infe-
rior, Anterior, and Posterior surfaces. 5, Ridge
for Temporal Fascia. 6, Parietal Foramen. T and
8. Inferior angles.

AND PHYSIOLOGY

45

edge a large orifice for the
passage of the spinal mar-
row, just as it enters the
vertebrae. It is in the
most posterior part of the
skull, joining with the
sphenoid in front, and rest-
ing upon the Atlas verte-
bra. The Sphenoid Bone
is directly underneath the
skull, extending from side
to side, forming a very
small portion of the out-
side of the skull at the

Fig. 48.

External surface of Occipital Bone. 1 and 4,
Semicircular Ridges. 2, Occipital Protube-
point where the frontal ranee, 3, Attachment of ligamentum nuclte,
, , -, 5, Foramen for Medulla oblongata. 6, Condylo

and temporal bones come of right side. 7 and 8, Condyloid Foramina.
the nearest to each other. ^' Jugular Eminence. 10, Jugular Foramen.
. 11, Basilar process. 12, Points of attachment

From Its name we learn for odontoid ligaments, is, Edge for attach-
ment with Parietal bone. 14, Point of attach*
ment for Temporal bone.

Fig. 49.

that it is somewhat wedge

The Anterior and Inferior Surface of the Sphenoid Bone. 1, 1, Apophyses of Ingras-
slas. 2, 2, The great Wings. 3, Ethmoidal Spine. 4, Azygos Process. 5, Sphenoidal
Cells, after the removal of the Pyramids of Wistar. 6, Posterior Clinoid Processes.
7, Sphenoidal Fissure. 8, Foramen Rotundiim. 9, Depression for the Middle Lobes of
th« Cerebrum. 10, Surface for the Temporal Muscle. 11, Styloid Process. 12, Exter-
nal Pterygoid Process. 13, Internal Pterygoid Process. 14, Pterygoid Foramen. 15, Ar-
ticular Face for the Os Frontis. 16, Points to the Sella Turcica.

48

HITCHCOCK'S ANATOMY

shaped in its general outline, although it is covered and
filled with cavities and processes for the protection and
proper direction of many of the delicate organs which pass
through it to their destination. This bone articulates with
all those in the cranium, and five of those in the face, and
serves as a point of attachment for twelve pairs of muscles,
and is one of the most complicated bones belonging to the
human skeleton.

The last bone of the skull is situated at the base of

Pig. 51.

Fig. 50.

An Upper, and Posterior View of the
Ethmoid Bone. 1, Nasal Lamella. 2, Body
or Cellular Portion. 8, Crista Galli. 4,
Cribriform Plate. 5, Superior Meatus.
6, Superior Turbinated Bone. 7, Middle
Turbinated Bone. S, Os Pli.niim. 9, Sur-
face for the Olfactory Nerve.

A View of the Outside of the Vault of
the Cranium, showing the Sutures. 1, The
Coronal Suture. 2, The Sagittal Suture.
8, The Lambdoidal Suture.

the front portion of the cranium, between the sockets of
the eyes, and behind the root of the nose. It is called the
Ethmoid Bone. Its outline is that of a cube, consisting of a
perpendicular plate, and two lateral portions. From the
fact that it is extremely fragile, owing to the great number
of perforations which it contains, it derives its name from the
Greek word signifying a sieve. It is so deeply seated that it
receives the attachments of no muscles.

108. Sutures. — The bones of the skull are united by

Give the shape and position of the Ethmoid bone. Why called Ethmoid?

AND PHYSIOLOGY

47

ragged edges called Sutures. These are small and rough
projections of bone which are largest at their extremities.
Thej are made to fit into the edges of the opposite bone with
great firmness, thus joining the bones together, by essentially
the same process which in cabinet work is known as dovetail-
ing. The name Suture is applied, since when these edges
are perfectly joined by this 'articulation, they resemble the
seam made by sewing together two pieces of cloth by the
"over and over" stitch. Situated directly within these sut-
ures are frequently found
small bones, uncertain as to
number, sometimes two inches
in diameter, called Ossa Tri-
quetra. No special use for
them has been discovered as
yet.

109. The Lower Surface
of the Skull.— The whole of
the lower surface of the skull
is extremely uneven for the
attachment of a great number
of muscles, and the protection
of delicate nerves and blood-
vessels which pass to and
from the brain and face.

110. Bones in the Face. —
The Face is that portion of
the head situated below a line
drawn from the orbit of the
eye to the passage of the in-
ternal ear. Its framework con-
tains fourteen bones. 2 Nasal ;

A Front View-
Bones coiiii)osin£

of the Skull, showing tho
the Face. 1, Os Frontis.
2, Nasal Tuberosit}-. 3, Supra-Orbital Ridge.
4, Optic Foramen. 5, Sphenoidal Fissure.
6, Sjilieno-MaxiUary Fissure. 7, Lachrjnnal
Fossa, and conuneuceuient of the Nasal Duct.
8, Opening of the Anterior Nares, and tho
Von)er. 9, Infra-Orbital Foramen. 10, Ma-
lar Bone. 11, Symjihysis of the Lower Jaw.
12, Anterior Mental Foramen. 13, Ramus of
the lower Jawbone. 14, Parietal Bone. 15,
Coronal Suture, 16, Temporal Bone. 17,
Squamous Suture. 18, Great Wing of tho
Splienoid. 19, Commencenu^nt of the Tem-
poral Ridi:e. 20, Zygomatic Process. 21, Mas-
toid Process.

IIow do the bones of the skull join with each other ? What process in cabinet making
doe.s it correspond to ? What are often found in these sutures? 109. What is the sur-
fivco of tba lower part of the skull ? 1 10. Q-Ive tho boundaries of the face.

3

AB

HITCHCOCK'S A X A T O 31 Y

2 Malar; 2 Lachrymal; 2 Superior Maxillarj; 2 Palate:
2 Turbinated ; 1 Inferior Maxillary ; 1 Vomer.

111. Nasal Bones . — The Nasal Bones are oblong, foursided
bones, about an inch in length, which together form the
bridge or base of the nose.

Tick 53.

Fig. 54.

An Anterior and Posterior Yiew of the
Nasal Bones. Right Hand Figure. 1, An-
terior Inferior Extremity. 2, Articulating
Surfixce for its Fellow. 3, Surface for the
Nasal Process of the Superior Maxillary
Bone. 4, Points to the Groove on the In-
ner Side, for the Nasal Nerve. 5, Articu-
lar Face for the Os Frontis. C, Foramen
for the Nutritious Artery. — Left Hand
Figure, 1, Posterior Inferior Extremity.
'2, Surface for its Fellow. 3, Surface for
the Superior Maxilla. 4, Groove for the
Internal Nasal Nerve. 5, Surface for the
Cs Frontis. 6, Lower portion of the
Groove for the Nasal Nerve.

An Anterior Yiew of the Malar Bona
of the Eight Side. 1, Anterior Orcital
Angle. 2, Orbital Face. 3, Superior An-
gle for articulating with the Os Frontis.
4, External An-le for the Zygoma of the
Temporal Bone. 5 and G, Inferior An-
gle and Surface for the Superior Manilla.
7, Nutritious Foramen.

112. Malar Bones.— The Malar Bones giye the promi-
nence and form to the cheek. They are partially hollow, of
an irregularly quadrangular outline, and articulate with the
frontal aboYC, the zygomatic process of the temporal behind,
and the superior maxillary below. The name is from the
Latin Mala^ a " cheek," hence cheek bones.

113. Lachrymal Bones. — The Lachrymal Bones are the

How many bones in the Face, and what are their names? 111. Describe the Nasal
Bones. 1 12. What bongs are found in the cheeks ?

AND PHYSIOLOGY

49

smallest bones in the Face, being about |th of an inch in
diameter. They are situated at the inner angle of the eye,
and are named from the Latin Lachryma^ a " tear." since
the tears pass into the nostrils through a canal in these
bones. This bone is also called Os Unoruis.

Fig. 56.

Fig. 55.

An Anterior Yiew of the Os Un-
guis of the Left Side. 1, Its An-
terior Inferior Angle. 2, Orbitar
Plate and Side for the Os Pla-
num. 3, Fossa for the Lachry-
mal'Sac. 4, Superior Extremity.

A Posterior and Half Lateral View of the Pal-
ate Bono. 1, Palate Plate on its Nasal Surface.
2, Nasal Plate. 3, Pterygoid Process. 4, Sur-
face for Articulating with its fellow. 5, Half
of the Crescentic Edge and Spine for the Azygos
Uvula? Muscle. 6, Eidge for the Inferior Spongy
Bone. 7, Spheno-Palatine Foramen. 8, Orbital
Plate. 9, Pterygoid Apophysis. 10, Depression for the External Pterygoid
Process of the Sphenoid Bone. 11, Same for the Internal Pterygoid Process.

114. Palate Bones. — The Palate Bones are the most ir-
regular bones of the face, and ^vhen viewed in one direction
resemble the capital letter L. They form a part of the orbit

of. the eye, the wall of the
nose, and a large part of the
roof of the mouth which is
known as the hard palate.

115. Turbiiial Bones. —
The Turbinal Bones (really
the Inferior Turbinated
Bones, since corresponding
plates upon the ethmoid bone
are called Superior Turbinated

Fig. 5T.

An External View of the Inferior
Spongy Bone of the Ptight Side. 1, An-
terior Extremity, for resting on the
Kidge of the Upper Maxilla. 2, Posterior
for resting on the Ridge of the Palate
Bone. 3, Hooked portion, for resting on
the Lower Margin of the Antrum Iligh-
morianuin. 4, Its Inferior Border.

113. What are the smallest bones of tlio face, and wliy called Laclu-ymal ? 114. What
arc the most irregularly-shaped bones in the face, and ^^■hat portion of the mouth Is
made up by the Palate Bones? 115. Give the description of the Turbraal Bone*.

50

HITCHCOCK'S ANATOilY

Bones) are curved laminse or thin plates of bone, resembling
a loose scroll, and are found in each nostril, for the purpose
of affording as large a surface as possible for the expansion
of the mucous membrane of the nose, which contains the
nerves of smell. The name Turbinal or Turbinated is ap-
plied because of their scroll-like appearance.

116. Superior Maxillary Bone.— The Superior Maxilla-
ries are the largest bones of the face, joining with each other
FiCr. 58. Fig. 59.

An External View of the Superior Max-
illa of tho Left Side. 1, Orbitar Process.
2, Infi-a-Orbitar Canal. 3, Space for tho
Os Unguis. 4. Upper part of the Lachry-
mal Canal. 5, Nasal Process, and Sur-
L\ce for Articulating with the Os Frontis.
G, Surface for the Nasal Bone. T, Anterior
portion of the Floor of the Nostril. 8, Sur-
face for Articulating with its Fellow. 9, Al-
veolar Process. 10, Points to the Depression
j'lst below tho Infra-Orbitar Foramen. 11,
iiurfuce for tho Malar Bone.

Tho Inferior Maxillary Bone. 1, The
Body. 2, The Eamus. 3, The Symphy-
sis. 4, Alveolar Process. 5, Anterior
Mental Foramen. 6, The Base. 7,
Groove for the Facial Artery. 8, Tho
Angle. 9, Extremity of the Eidge for
the Mylo-Uyoid Muscle. 10, Coronoid
Process. 11, Condyle. 12, Neck of tho
Condyloid Process. 13, Posterior Men-
t.J Foramen. 14, Groove for the Infe-
rior Maxillary Nerve. 15, Molar Teeth.
13, ricuspidate Teeth. 17, IS, Middle

and Lateral Incisors.

on the median line, and thus form a portion of the roof of
the mouth. Each one of them articulates with eight teeth,
with all the bones of the face but the lower jaw, and two of
the cranium. Their name is from tho Latin, MaxLla, a
"jaw," and both of them constitute the upper jaw.

117. lilandiblc. — The Inferior Maxillary, or lower jaw, is

116. How aro tho Superior Maxillaries situated!
of thorn ? 117. Describe the Maodlblo.

llow many teeth aro found in each

AND PHYSIOLOGY.

sr

the only movable bone of the head or face. It contains the
sixteen lovfer teeth, is of an arched form, and at each ex-
tremity has a square-shaped process for articulation ^vith the
temporal bones, and the attachment of muscles.

118. Vomer.— The
name of the Vomer is
derived from the Latin
meaning a "plow-

FiG. 60,

share,

on

account of

its approximate resem-
blance to that object.
It completely separates
the nostrils from each
other, and like the tur-
binated bones gives at-
tachment to no mus-
cles.

<i 0'

\

• \

The Tomer, 1, 2, Posterior and Superior Surface ^

hollowed to receive the Azygos Process of tho
Sphenoid Bone. 3, Anterior Surface for the Car.
tilaginous Septum of the Nose. j

119. Number of Teeth.— The Teeth of the Human Adult
-when all present in the jaws, number thirty-two. And al-
though properly bones, still they differ in three respects :

1st, Oj'ganic Composition.

2nd, Time of Development and Replacement.

3d, Decay w^hen fractured.

120. Organic Composition, Cemcntum, Dentine, Enamel,
Microscopic Structure of Enamel, Development of Teeth,
Nasmyth's Membrane.— The Teeth are composed of three
substances : a Cementum which forms a thin coating on the
fangs of the teeth, and which thickens in advanced life ; the
Dentine which resembles bone in its external characteristics
and makes the largest part of the teeth, containing the prin-
cipal vessels and nerves of the teeth ; and the Enamel, the
hardest substance in the human body, which is a covering to

lis. From -what does the Vomer derive its name ? What two cavities does it sep-
arate ? 119. How many teeth in an adult? In what respects do they differ from the other
bones of the body ? 120. Of what substances are the teeth composed?

52

HITCHCOCK'S ANATOMY

Fig. 61. Fig. 62.

Vertical Section of Human Incisor, a,
the point wliere the Gum is attached to
the Tooth.

Fig. 63.

Fig. 64.

A Yie-w of an Incisor and of a Molar
Tooth, given by a Longitudinal Section,
and showing that the Enamel is striated
and that the Stria) are all turned to the
center. The Internal Structure is also
Been. 1, The Enamel. 2, The Ivory. 3,
The Cavitas Pulpi.

A Vertical Section of an Adult Bicuspid,
cut from without inwards ; magnified four
times. 1, 1, The Cementum which sur-
rounds the Eoot up to the commencement
of the Enamel. 2, 2, The Dentine of
the Tooth, in which are seen the greater
Parallel Curvatures, as well as the position
of the Main Tubes. 3, Apex of the Tooth,
where the Tubes are almost perpendicular.
4, 4, The Enamel. 5, The Cavity of tho
Pulp, in which are seen, by means of the Glass,
the Openings of the Tubes of the Dental Bone.

all the tooth above the gums.
This is a pure white sub-
stance, thickest upon the top
of the crown, and gradually
growing thinner towards the
gum, where it disappears al-
together. Under the micro-
scope it is seen to be made
up of minute hexagonal fibers,
one end of which rests upon
the Dentine, and the other
forms the free surface of the
tooth. These tubes or fibres
are slightly undulating and

AND PHYSIOLOGY

53

from joVoth to ^Tw^d of an
inch in diameter. The en-
amel is also covered by a very
thin membrane, rifsist of an
inch in diameter, called Nas-
myth's membrane. This is
a " calcified" membrane and
can be seen only with great
care, since it is not acted up-
on by the strongest acids or
alkalies.

Fig. 65.

A portion of the Surfivce of the Enamel
on which the Hexasconal Terminations of
tlie fibres are shown ; highly magnified.
1 2, 8, Are more strongly marked dark,
crooked Crevices, running between the
rows of the Hexagonal Fibres.

121. Development of Teeth.
Temporary Set. Permanent
Set. — The teeth in the human subject are not perfectly formed
at birth, but exist in the form of follicles or shut sacs, which
at the seventh or eighth month of infantile life, are developed
into teeth. The process of dentition generally occupies from
one to three years, during which time the temporary set, as
it is termed, make their appearance. These number twenty,
ten in each jaw, and between the age of seven and fourteen
become loose, and are easily removed to give place to the per-
manent set which numbers thirty-two. Generally, however,
the last tooth in each jaw does not make its appearance until
the twentieth year of life.

122. A more accurate statement of dentition of the tempo-
rary teeth shows that they appear at the following ages :

The Incisors, from the 1th to the 10th month.
The Anterior Molars, 12th " 13th "
The Canine Teeth, 14th " 20th "
Posterior Molars, 18 th " 36 th "

123. The permanent teeth appear as follows :

Describe each of the teeth. What membrane completely covers tho outside of tho-
tooth? 121. niustrate the development of the teeth, 122. Give the time of appearance
of the temporary teeth. 123. When do the permanent teeth appear ?

54

HITCHCOCK'S ANATOMY

Incisors, from the 8th to tlie 9th year.
Bicuspids, 10th " 11th '''

Canines, 12th " 12ith "

Second Molars, 12 Uh " 14th "

Third Molars

ITth

19th

124. Names of Teeth. — A third set of teeth has been
known to make its appearance ; also a tooth extracted and
at once replaced maj become firm again at the end of some
months.

The names and number of the permanent teeth in each
jaw, beginning at the posterior part of the mouth, are :

■ 2 Wisdom, 4 Molars, 4 Bicuspids, 2 Canine, 4 Incisors.

a l e d 6 f g h

a, l>, Incisors, c, Canine, d, e, BicuspiJs. /. g, MoIsj-s. h. Wisdom teeth.

125. Fracture of Teeth. — All the bones o£ the body, ex-
cept the teeth, when broken will become united again ; but if
the teeth lose a portion of their enamel, or even if it be
cracked, the tooth so injured at once begins to decay, and
will be entirely consumed, unless the disease be checked by
artificial means.

124. What is said about a third set? Give the names of the permanent t«cth.
125. What it tlie teeth ure broken or cracked ?

AND PHYSIOLOGY.

55

An Anterior View of the Os Ilyoides,

1, Thf^ Anterior Convex Side oi tlie Body.

2, The Cornu Majus of the Left Side. 3,
The Cornii Minns of the same Side. Tho
Cornua were ossified to the Body of tho
Bone, in this specimen.

126. Hyoid Bone. — The fig. gt.
Hjoid Bone is the bone which
forms the base of the tongue,
and the upper extremity of
the trachea. It has the
shape of the Greek letter U
(or Upsilon) and articulates
with no other bones, but is
completely enveloped bj the
soft parts. It has a consi-
derable range of motion in a

vertical direction, and hence gives attachment to no less
than eleven pairs of muscles.

127. Sternum. — The Breast Bone is flat, about eight
inches in length, one and a half in width, and is located on
the median line of the bodj upon the front portion of the tho-
rax or chest, articulating with the seven upper ribs on both
sides, and also with the clavicle.

128. Ribs. — There are twentj-four ribs in the human

Fig. G8. '\-yfm^^^ Fig. 69.

A View of the Upper Side of the First
Eib of the Right Side, half the size of na-
ture. 1, The Head. 2. The Tubercle. 3,
Anterior Surface. 4, Groove for the Sub-
clavian Artery. 5, Groove for the Sub-
clavian Vein. 6, Anterior E.xtreuiity for
A Front View of the Sternum. 1, First the Cartilage. T, Tubercle for the Scalenus

Piece. 2, Second Piece. 3, Ensiform Car- Anticus Muscle.

tilagc, or Third Piece. 4, Articular Face

for the Clavicle, 5, Articular Face for the First Eib, 6, Articular Face for the Soconl

Eib, 7, S, 9, 10, Articular Faces for the Last Five Time Elba.

126. Where is the Hyoid Bone? What Greek letter does it resemble ? 127. Describe
tho Sternum, With what bones does it articulate ? 12S, Number oi Eibs in man?

3*

56

HITCHCOCK'S ANATOMY

Fig. 10,

General Character of the other Eibs, seen on their Upper and Under Surface. T/i6
lefnxand figure is the Upper Face of the Rib. 1, Head of the Eib. 2, Its Tubercle.
3, Anterior Extremity for the attachment of the Costal Cartilage. 4, Groove for the Ar-
tery and Nerve. 5, Angle of the Rib. The right hand figure is the Under Surface of
the Rib. 1, The Head. 2, Its Tubercle. 3, ^interior Extremity. 4, Groove for Inter-
costal Artery and Nerve. 5, Angle of the Eib.

body, which are divided into two classes, the true and the
false, or those which are closely united with the sternum,
and those which are remotely attached to it by long cartilages.
They are attached at their posterior extremities to the verte-
brae, and run downwards and forwards, so that when elevated,

Fig. n.

Vertebral Column.

Eibs.

Intercostal Muscles,

Clavicle.

, .Third Eib.

- Stefnum.

Seventh Eib.

False BlU.

AND PHYSIOLOGY

57:

they enlarge the cavitj of the chest. The true ribs are the
seven uppermost ones, and the false the five lower ones, and
are so arranged that thej form a cone with the apex at the
neck. The two lowest ribs are sometimes called '^ floating,'^
because thej are only attached to the vertebrse.

Fig. 72.

An Anterior View of the Clavicle of tlic Eight
Side. 1, The Anterior Face of the Body of the Bone.
2, Origin of the Clavicular por:ion of the Steino-
Cleido-Mastoid Muscle. 3, Tlie Sternal Extremity of
the Bone. 4, The Acromial Extremity of the Bone.
5, Articular Face for the Acromion Process of the Scapu-
la. 6, Point of Attachment of the Conoid Ligament.
7, Point of Attachment of the Rhomboid Ligament.

129. Clavicle.—
The Collar Bone is the
commencement o f
the upper extremity.
It is one of the class
of long bones ex-
tending from the
highest point of the
scapula to the upper
part of the sternum,
and bears a partial
resemblance to the
Italic letter F. The name is from the Latin C^avis^ "'a
key," since it remotely resembles an antique key.

130. Scapula. — A large, flat, and triangular bone upon
the upper part of the back, and forming the shoulder, is
called the Scapula, or Shoulder Blade. It has a high and
narrow ridge running through its longest diameter, which is
the bone so distinctly felt upon the shoulder and upper part
of the back. Its only articulations are with the clavicle and
humerus, the posterior part being kept in its place by mus-
cles and ligaments. (Fig. 73, p. 58).

131. Humerus. — The Humerus is the bone of the uppsr
arm or shoulder. (Fig. 74, p. 58.) It is a long bone with
a cylindrical shaft, and has a rounded head for its upper ex-
tremity. The lower extremity is flattened from before back-

What two classes are they divided into? What do they all nnite with behind?
129. What two bones does the Clavicle unite with ? 130. What is the general outline of
the Scapula ? Where is it located ? What are its only articulations ? 131. What is the
bone of the upper arm ?

5S

HITCHCOCK'S ANATOMY

Pig. 73. Fig. 74-.

A Posterior View ot the Scapula of tLo
Left Side. 1, Fossa Supra-Spinata. 2, Fos-
sa Infra-Spinata. 3, Superior Margin. 4,
Coracoid Notch. 5, Inferior Margin. 6,
Glenoid Cavity. 7, Inferior Angle. 8, The
Neck and Point of Origin of the Long Head
of the Triceps Muscle. 9, Posterior, or
Vertebral Margin. 10, The Spine. 11,
Smooth Facet for the Trapezius Muscle.
12, Acromion Process. 13, Nutritious Fo-
ramen. 14, Coracoid Process. 15, Part of
the Origin of the Deltoid Muscle.

An Anterior View of the Humerus of the
Eight Side. 1, The Shaft, or Diaphysis of
the Bone. 2, The Head. 3, Anatomical
Neck. 4, Greater Tuberosity. 5, Lesser
Tuberosity. 6, The Bicipital Groove. 7,
External Bicipital Eidge for the insertion
of the Pectoralis Major. 8, Internal Bici-
pital Eidge. 9, Point of insertion of the Deltoid Muscle. 10, Nutritious Foramen.
11, Articular Face for the Head of the Eadius. 12, Articular Face for the Ulna.
13, External Condyle. 14, Internal Condyle. 15, 16, The Condyloid Eidges. 17,
Lesser Sigmoid Cavity.

wards, and so formed into grooves and elevations that it ar-
ticulates with the ulna in essentially the same manner as the
two portions of a door hinge.

132. Fore- arm. The Ulna. — There are two bones in the
forearm, one of which onlj is articulated with the humerus,
and the other to the bones of the wrist alone, in order to al-
low the rotation of the hand upon the bones of the forearm,

What is the shape of the lower, or ulnar articulation ? 132, How many bones in the
fureaxui? Why are there two instca/1 of one?

AND PHYSIOLOGY.

59

as if they constituted a pivot ; ^^^- *^^-

an instance of which is seen in
the turning of a screw, or in
the unlocking of a door. Of
these two bones the Ulna arti-
culates with the humerus, form-
ing only a ligamentous union
with the bones of the wrist.
It is prismoid in form, and is
of a hooked shape at its up-
per extremity, so that it
makes the union between it-
self and the humerus a very
secure one. The word ulna
is a Latin term signifying an
ell, because the forearm in
early times was used for that
measure.

133. The Radius The

Kadius is the mate of the
ulna. Its upper extremity is
the smallest, and the lower
the largest, since its only true
articulation is at the wrist.
A firm membrane, however,

unites this bone to its fellow nearly its whole length. It prob-
ably derives its name from the fact that it measures the ra-
dius of a circle which may be described by the hand about
the elbow as a center.

134. The Carpus. — The bones of the Carpus or Wrist are
eight in number, are small and irregular, and have the gen-
eral disposition of two rows. The first row, commencing with
the one nearest the thumb, contains the Scaphoid, Semilunar,

..#^^

Bones of the Forearm. 1, S'lio Ulna.
2 and 3, The Sigmoid Notches. 4, The
Olecranon Process. 5, Coronoid Process.
6, Nutritions Foramen. 7. Ridge for at-
tachment of Interosseous Membrane. 8,
Capitulnm L'lniie. 9, Styloid Process. 10,
Shaft of the Kadius. 11, 12 and 18, Head,
Neck, and Tuberosity of Eadius. 14, Ob-
lique Line for muscular attachments. 15,
styloid Process.

In what operations do we need the two bones of the forearm ? Give the derivation of
ulna. 13.5. What is the mate "of the ulna? Where does this articiilatc? What is tho"
derivation of its name? 134. lloi*' many bonos in the wrist? Give their nomes.

60

HITCHCOCK'S ANATOMY

Fig. 16. ' Fig. 11.

A Posterior A^iew of the Articulations
of the Bones of the Carpus in the Eight
Hand. 1, The Ulna. 2, The Eadius. 3,
Inter-Articular Fibro-Cartila2;e. 4, Meta-
carpal Bone of the Thumb. 5, Metacarpal
Bone of the First Finger. C, Metacarpal
Bone of the Second Finger. 7, Metacar-
pal Bone of the Third Finger. 8, Meta-
carpal Bone of the Fourth Finger. S, The
Scaphoides. L. The Lunare. C, The Cu-
neiforme, P, The Pisiformo. T, T, Tra-
pezium and Trapezoides. M, The Mag-
num. U, The Unciforme.

An Anterior Yiew of the Left Hand.
1, The Scaphoides. 2, The Lunare. 3,
The Cuneiforme. 4, The Pisiforme. 5,
The Trapezium. C, Groove for the Flexor
Carpi Eadialis Tendon. 7, The Trape-
zoides. S, The Magnum. 9, The Unci-
forme. 10, 10, The Five Jlcta-Carpal
Bones. 11, 11, First Eow of Phalanges.
12, 12, Second Eow of Phalanges. 13, 13,
Third Eow of Phalanges. 14. First Pha-
lanx of the Thumb. 15, Last Phalanx of
the Thumb.

Cuneiform, and Pisiform. The second in the same order, the
Trapezium, Trapezoid, Magnum, and Unciform.

135. The Metacarpus. — The Metacarpus contains five
bones. Each of these articulate with the carpus above, and
the phalanges below, being found in the space known as the
palm or body of the hand.

136. The Phalanges. — The Phalanges are the bones of
the thumb and fingers, two in the former, and three in the
latter, making fourteen in each hand.

IZb. Describe the Metacarpal Bones. What part of the hand do they occupy?
136. IIow many Phalanges in the thumb, and how many io each finger ? What is tha
whole number of them ? • ■ .

AND PHYSIOLOGY.

61

187. Cones of the Pelvis. — The bones of the Pelvis are
the two Innominata or nameless bones, and the Sacrum and
CoccyXj which have already been described. (Fig. 78.)

Fig. 13.

138. The Innominatum, Ilium, Ischium, Pubes. — Each
Innominatum presents the largest surface of any bone in the
body. They are irregularly flat bones and situated just
beneath the abdomen, to the organs of which they give firm
support by their broadly-expanded surface. In young skele-
tons they are divided into three portions, and hence they are
described in the adult as made up of three parts, although no
line of division can actually be seen. The Ilium constitutes
the broadly-expanded portion usually known as the hip or
haunch. The Ischium, from the Greek signifying to ''hold"
or *• retain," is the heavy portion projecting downwards, and
that point on which the body rests, when in a sitting posture.

137. IIow many bones in the Pelvis, and what are their names? 13S. Describo tho
Innominatum. Into how many parts are they . divided in young animals? Describo
tho Ilium and tho lachiuai.

62

HITCHCOCK'S ANATOSIT

Fig. 19.

Outside of the Innominatutn of the Eight Side.
1, Dorsum of the Ilium. 2, Iscliium. 3, Pubis.
4, Crest of the Ilium. 5, Surface of the Gluteus
Medius. C, Surface for the Gluteus Minimus.
7, Surface for the Gluteus Maximus. 8, Anterior
Superior Spinous Process. 9, Anterior Inferior
Spinous Process. 10, Posterior Superior Spin-
ous Process. 11, Posterior Inferior Spinous
Process. 12, Spine of the Ischium. 13, Greater
Sacro-Sciatic Notch. 14, Lesser Sacro-Sciatic
!No:ch. 15, Tuber Ischii. 16, xiscending llamus
of the Ischium. 17, Body of the Pubis. IS, Ra-
mus of the Pubis. 19, Acetabulum. 20, Thyroid
roramcn.

the Bone. 8, The

An An'erior View of the Femur o
the Ilight Side. 1, Depressifni for
the Round Ligament. 2, The Head.
8, The Neck. 4, Trochanter Major.
5, Trochanter Minor. 6, Surface for
the Capsular Ligament. 7, Shaft of
External Condyle. 9, The Internal

Condyle. 10, Surface for the Patella.

The Pubis is tlie most central and anterior portion. These
three divisions unite at the point known ss the acetabulum or
receptacle for the head of the femur, which is a perfect hemi-
spherical cup lined with cartilage.

139. The Femur. —The Femur is nearly two feet in length,
and consequently the longest bone in the body, commonly
known as the Thigh Bone. At its upper portion it makes a

109. What is the average length of tlio Femur? Give its general features. What ii
the longest bono i a tho body ?

AND PHYSIOLOGY. 63

sudden bend inwards, forming the neck of the bone, the ter-
mination of which is hemispherical, in order to articulate with
the innominatum, forming the ball and socket joint. Its
lower extremity has two large condyles or processes, for the
purpose of giving attachments to the ligaments of the knee,
and articulating with the tibia.

140. The Patella —Or Knee Pan is the ^ig. si.
largest sesamoid bone in the body. It arti-
culates with the femur, and lies imbedded in
the extensor tendon of the thigh. The chief
value of this bone is to give a change of
direction to the force of the muscles which
move the lower bones of this extremity we
are now describing. Patella in Latin signi- ^^ ^^J^.^^ ^.^^. ^j
fies a "plate," and hence the name of this thePatciia. i, 2, sur-

- - ■"• ^. , , ,. face for the Quadriceps

bone, because 01 its rounded outline. remoris Tendon. 3,

Lower Extremity and

141. The Tibia.— That portion of the roint of origin of the

, • 1 1 11 1 • 1 • Ligainentum Patella?.

lower extremity below the knee, which is
properly the leg, has two bones called crural for its frame-
work. The largest of these is the Tibia (Fig. 82, p. 64.) It
is somewhat triangular in its general outline, having its
upper extremity depressed in two places for the reception
of the condyles of the femur. Besides the femur above,
it articulates with the fibula and astragalus below. The
name tibia is given to the bone, since it resembles, though
remotely, the ancient Phrygian flute.

142. T!ic Fibula.— The Fibula is the other bone of the
leg:, loner and slender. It articulates at each end with the
tibia. The meaning of the Latin fibula^ is a ''pin," or
fastening of a clasp, owing to its slender form. The lower
extremity of this bone, and also that of the tibia, forms what

140. Describe the Patella or Knee Pan. In what is it imbedded? 141. What is the
Leg? What are the two bones of it? Which is the largest and consequently most im-
portant one ? 142. Give the general descriptiou of the Fibula. What compose the ex-
ternal and internal Malleoli ?

64

HITCHCOCK'S A I^ A T O il Y
Fig. 82. Fig. 83.

Eight Tibia and Fibula. 1, Tibia. 2
and 3, Inner and Outer Tuberosity. 4,
Sjjihous Process. 5, Tubercle for attach-
ment of Muscles of the Thigh. 6, Edge of
Tibia. 8, Internal Ancle. 9, The Fibula.
10 and 11, Extremities of Fibula.

A Yiew of the Upper Surface of the Left
Foot. 1, The Astragalus on its Upper
Face. 2, Its Anterior Face, Articulating
■with the Naviculare. 3, The Os Cahus.
4, Naviculare, or Scaphoides. 5, The In-
ternal Cuneiform. 6, The Middle Cunei-
form. 7, The External Cuneitbrni. 8,
The Cuboid Bone. 9, 9, Metatarsal Bones.
10, First Phalanx of the Big Toe. 11, Sec-
ond Phalanx of the Big Toe. 12, 12, 13,

13, 14, 14, The First, Second and Third Phalanges of the other Toes.

are known as the external and internal malleolus, or the two
long projections on each side of the ancle.

143. The Tarsus. — The Tarsus is made up of seven ir-
regular bones, forming the instep of the foot. The Astra-
galus is of a cubical form (so named from its resemblance
to the die, used in games of chance) and supports the tibia
alone. The Os Calcis, meaning the bone of the heel, is the
largest of the bones of the tarsus, and is irregularly cubical

143. How many bones make up the Tarsus ? Why is the uppermost called the Astra'
galus ? Which is the largest of these bones ?

AND PUYSIOLOGY. 65^

in form, making, bj a decided projection, the heel. Directly
beneath and anterior to the last two, are found the Cuboid
(cube-shaped) and the Scaphoid (boat-shaped), and anterior
to these the three Cuneiform (wedge-shaped), articulating
with the metatarsal bones in front.

144. Metatarsal Bones. — These are five in number, and
correspond with those in the metacarpus, except that the one
in the first toe is of equal length with the others, and does not
admit of so free motion as that of the thumb.

145. The Phalanges. — The Phalanges of the foot are also
like those of the hand, except that in the foot the first row is
the longest, while in the hand it is in the third row or second
finger.

146. Sesamoid Bones. — Besides the bones already men-
tioned, there are frequently found in stout adult men small
bones, or portions of bony matter called Sesamoid Bones,
from their resemblance to the Sesamum, a kind of bean.
And although they are not constant either in individuals, or
in the same places in the individual, yet anatomists are
accustomed to reckon eight, or four pairs as the normal
number. They are all found enclosed in tendons, and serve
like the patella to change the direction of motion. They
are found at the point where the tendon glides over the
joint made by the phalanges and metatarsus of the foot,
and the metacarpus of the hand, in the tendon which plays
over the under surface of the cuboid bone in the foot ; and
also in the tendons that glide over the lower condyles of
the femur.

147. Bones of the Ear. — In the Ear are three bones
which will be more appropriately described with the organ
itself

148. Number of Bones. Single Bones.— Of the 246

144. How many Metatarsal Bones ? 145. How many Phalanges of the Foot? How
do they diflfer from those of the hand ? 146. Describe Sesamoid Bones. How many are
there, and where are they generally found ? 147. How many bones of the Ear?

66 HITCHCOCK'S ANATOMY

bones found in the human body, all but thirtj-four are found
in pairs, or one upon each side of the body. The single
bones are the frontal, occipital, ethmoid, sphenoid, vomer,
mandible, hyoid, sternum, twenty-four vertebrse, the sa-
crum and the coccyx.

SYNDESMOLOGY.

DE3CEIPTI0N OF THE LIGAMENTS.

149. Rinds of Articulation. — The modes or manner of
connection between the different bones of the body are three :
Synarthrosis, Amphiarthrosis, and Diarthrosis. The first of
these modes, means the joining of such bones as have no
motion between them ; the second, a joint with the aptitude
for movement between the immovable synarthrosis on the one
hand, and the movable diarthrosis on the other ; the third, a
movable articulation, which constitutes by fir the greater
part of the joints of the body.

150. Sutura, Ilarmonia, Scliindylesis, Gompliosis. — Of
Synarthrosis there are four varieties : first, Sutura, the ar-
ticulation between the bones of the skull by ragged inter-
locking edges ; second, Harmonia, that between the two upper
maxillaries, where the bones with comparatively straight
edges are simply placed edge to edge ; third. Schindylesis, or
the joint between the vomer and sphenoid, where the ex-
panded edge of one bone is fitted into a corresponding groove
in the other ; fourth, Gomphosis, the articulation of the teeth
with the jaws, and so named since it resembles the manner
in which a common nail is driven into a plank.

148. How many bones in the human body are found in pairs? Give the names of t]io
unmated bones. 149. How many modes of connecting the bones together? Describo
each. 150. Give the peculiarities of Sutura, of Harmonia, of Schindylesis, and of Gom-
phosis. Give an example of tho latter.

A X D PHYSIOLOGY. 67

151. Symphyses. — Of Amphiarthrosis there is but one
kind, the Symphyses, or the apposition of two bones with
simply cartilage between. Examples of this are the arti-
culations of the vertebrae, and the ossa pubis.

152. Arthrodia, Giiiglymiis, Enarthrosis.— Of Diarthro-
sis there are three Vi>ri3ties : Arthrodia, Ginglymus, and En-
arthrosis. Arthrodia is a slightly movable joint, as of the
wrist and ancle bones, or the radius and ulna. Ginglymus
is the common hinge joint, where the degree of movement
is very considerable, but only in two directions. The best
example of this is in the knee. Enarthrosis is the ball and
socket joint, that admits of movement in all directions. The
only cases of this articulation are in the shoulder, hip, and
thumb.

153. Anatomy of the Articulations. — In synarthrosis
there is simply a membrane interposed between the two bones
which keeps them in their places. In amphiarthrosis the
two extremities are partly covered with cartilage, lined by
synovial membrane, and partly connected by the interosseous
ligaments, or by an elastic fibro-cartilage which adheres to
both edges of the bones. In diarthrosis especially, as it is
exhibited in ginglymus, the general outline of the bone is
quadrilateral, upon each edge of which is found a ligament.
The lateral ones, however, are the main supports of the joint,
while the anterior and posterior ones are thin and a part of
the lime loose, which are only of service to determine the
amount of movement in the joint. An example of this is
seen in the fingers, since they can only be extended so as
to lie in the axis of the metacarpal bones. The reason
why they can not be bent back upon the dorsal surface oS
the hand is that the anterior ligament does not admit of sufii-

151, Describe the Symphyses. Give an example, 152. Give the three varieties of Diar-
throsis. Give an example of Arthrodia, Ginglymus, and Enarthrosis. 153. What aro
the component parts of the different articulations? Give the mode of articulation ot
tho lingers. Why can not the finger l>« bent upon tbo back of the hand?

68 HITCHCOCK'S A X A T O M Y

cient movement in that direction. In the knee, however,
there are thirteen ligaments.

154. Motions of the Joints. — The motions of the joints
may be comprised under four principal divisions : Gliding,
Angular movement, Circumduction, and Rotation.

155. Gliding. — Gliding movement is where the bones
simply slip over one another in the movement of the joint,
and exists to a greater or less extent in all the joints.

156. Angular. — Angular movement may be performed
in four directions : forwards and backwards, called flexion
and extension, and inwards and outwards, called adduction
and abduction. A joint, as the finger, h said to be flexed
when it is bent upon itself, that is upon the palm of the
hand, and extended when it u stretched to its fullest extent,
or as in the finger, when it is made straight with the bones of
the fore-arm. Adduction means the bringing of one of tho
extremities towards the body, or its fellow, while abduction
has the reverse signification.

157. Circumduction. — Circumduction can be performed
only by the ball and socket joints. It consists in carrying
the limb about the joint in a circular plane, or in other
words, describing a circle about the joint as a center.

158. Rotation. — Rotation u the movement of a bono upon
its own axis. A slight rotatory movement can be effected in
the joints of the shoulder and hip, but the best instance is
that of the radius rot itinoj asrainst the articular head of the
humerus, producing the subdivisions pronation and supina-
tion. Pronation consists in rotating the fore-arm so that the
palm of the hand shall be downwar;^s, and Supination the
reverse. Rotation is also observed in the movement of the
atlas upon the pivot of the axis.

154. What are the four motums of the joints ? , 155. Describe the Gliding movement.
156. In what four directions can Angular movements be ? 157. What is Circumductiou ?
15a Describe Rotation. What is rronatlon and Supination?

AND PIIYSIOLOGT.

69

159. structure of
Ligaments. Ar-
rangement of Liga-
ments. Capsular
Ligament. Round
Ligam ent. — The
bones are firmly
bound together bj
ligaments. These
are for the most
part bands of -white
glistening fibres, as
firm as steel, which
are composed of
white fibrous tis-
sue. They are gen-
erally very short,
and attached only
to the enlarged ex-
tremities of the
bone. In most of
the joints, and es-
pecially the gingly-
mus, the ligaments
are arranged in a
cross shape upon the
sides of tlie bones,
so that one l^one miy
glide freely over the
extremity of an-
other, as one half
of a door bin ore

o

moves upon its other
half In other in-
stances the ligament
surrounds tho whole

Fia. 84.

A tnngnifie.d View of a Vertical section- of Cartilago
from a new-born Rabbit, showing the progress towards
ossification. 1, The Ordinary appearance of Tempo-
rary Cartilage. 1', The same, more highly magnified.
2, The Primary Cells beginning to assume the linear
direction. 2', The same, more h.ighly magnified. 3»
The Ossification is extending in tho intercellular
spaces, and the rows of cells are seen resting in the
cavities so formed, the Nuclei being more separ-
ated than above. 8', The same, magnified more
highly, —^

ro

HITCHCOCK'S A X A T O il Y

Pig. 86.

An Anterior View of tho Ligaments of
the Pelvis. 1, The Lower part of the An-
terior Vertebral Ligament. 2, Tho Sacro-
Vertebral Ligament. 3, The Ilio-Lumbar
Ligament. 4, Tho Anterior portion of tho
Sacro-Iliac Ligament. 5, The Obturator
Ligament. 6, Poupart's Ligament. 7, That
portion of the same Avliich is known as
Gimbernat's Ligament. 8, The Capsular
Ligament of the Hip-Joint. 9, The Ac-
cessory Ligament of the Hip-Joint.

Ligaments from Shoulder-Joint 1, The
Superior Acromio-Clavicular Ligament.
2, The Coraco-Clavicular Ligament. -3,
The Coraco-Acromial Ligament. 4, Tho
Coracoifl Ligament. 5, The Capsular Liga-
ment of the Shoulder-Joint. 6, The Liga-
mentuxn Adscititium, or Coraco-Humeral
Ligament. 7, The Tendon of the Long
Head of the Biceps Muscle, issuing from
the Capsular Ligament.

joint, making it a shut sac, thus performing the double office
of keeping the two ends in contact, and of holding the lubri-
cating fluid in the joint. In addition to these, there is in
the ball and socket joint another kind of ligamentous attach-
ment between the two bones, called the round ligament, or
Ligamentum Teres. This is a bundle of ligamentous fibres
in the form of a cord, which is inserted into the summit of
the rounded head of the bone, and also in the bottom of the
cup-shaped cavity that receives the head. This is somewhat
lax ordinarily, but not so much so but that it keeps the head
from slipping out of its socket, and at the same time allows
the most perfect freedom of motion.

1J9. What are tho Ligaments ? To what part of tlio bones are they generally at-
tached ? How are they arranged in Ginglymus joints ? Why are they sometimes feaad
In tho foria of a shut S.-VC ■? Dcscriba the round lIgam«nU

AlfJ» PHYSIOLOGY
Fig. 87.

n

Fig. 88.

The Right Knee-Joint laid open.
1, The Lower End of the Femur cov-
ered by its Articular Curtilage. 2, Tho
Anterior Crucial Ligament. 3, Thu
Posterior Crucial Ligament. 4, Tho
Transvei'se Fasciculus adhering to
the Semilunar Cartilages. 5, Tho
Point of Attachment of the Ligamen-
tum Mucosura,tlie rest of it has been
removed. 6, The Internal Semilunar
Cartilage. 7, The External Semilunar
Cartilage'. 8, A part of the Ligamen-
tum Patellas turned downwards. 9,
Its Bursa laid open. 10, The Supe-
rior Peroneo-Tibial Articulation. 11,
The Interosseous Ligament.

A Lateral View of the Ligaments of the Hip-
Joint and Pelvis. 1, The Posterior Sacro-Iliac
Ligament of the Pelvis. 2, The greater Sacro-
Sciatic Ligament. 3, The Lesser Sacro-Sciatic
Ligament. 4, The Greater Sacro-Sciatic Notch.
r>, The Lesser Sacro-Sciatic Notch. 6, The Co-
tyloid Ligament around tho Acetabulum. 7,
The Ligamentum Teres. 8, The Line of At-
tachment of the Capsular Ligament of the Hip-
Joint, posteriorly. The Ligament has been
removed, in order to show tho Joint. 9, Tho
Obturator Ligament.

160. Aid of Atmosplieric Pressure. — Atmospheric pres-
sure also helps to keep the bones together. For since the
projection of one member so accurately fits the depression in
the other, and as the lubricating fluid makes the coupling
most perfect, the pressure of the atmosphere assists not a
little to keep the parts together.

16 i. I n 1 1' r - a r t i c u 1 a r C a r 1 11 a g c .^Another arrangement in
the joints is not a little singular, and well adapted to its pur-
pose. This is an interarticular cartilage in the knee called
semilunar, or a small disc of cartilage which lies loosely be-

160. What be3ide3 the ligaments heIx)S to keep the bones together ? 161. Describe tho
latdrarticular cartilage and its iiso.

^i HITCHCOCK'S ANATOMY

Fig. 89. Fig. ^0.

A View of the Articulation of the Lower
Jaw, given b.v sawing through the Joint.
1, The Glenoiil Fossa. 2, The Tubercle
for the Condyle in its Forward move-
ments. 8, Tlie Inter-Articular Cartilage.
4, The Sui)erior Sjniovial Cavity. 5, The
Inferior Synovial Cavity. C, The Intor-
Articular Cartilage removed from the stance.

An Anterior View of the Ligaments of
the Vertebra; and Kibs. 1, The Anterior
Vertebral Ligament. 2, The Anterior Costo-
vertebral Ligament. 3, The Internal
Transverse Ligament. 4, The Inter-Ar-
ticular Liaamcnt, connecting the Head
of the liib to the Intervertebral Sub-

Joint and .seen from below.

tween the bones. The design of it is to distribute the fric-
tion over a larger surface, as well as to diminish it.

Fig. 91.

162. In Fi-T. 90 we see

o

the mode of attachment be-
tween the vertebrae and ribs
which is that of three dis-
tinct ligaments to each rib,
besides one common to each
pair of ribs. Fig. 91 shows
the anatomy of the elbow-
joint. Here are no less
than four distinct lineaments.
We see in Fis;. 92 the liora-

An Internal View of the Elbow-Joint.
1, The Capsular Ligament. 2, 2, The In-
ternal Lateral Ligament. 3, The Coro-
nary Ligament. 4, The Ligamentum Te-
res. 5, The Interosseous Ligament. 6,
The Internal C(mdyle, which conceals the
Capsular Ligament behind.

1G2. Describe the ligaments in Figs. 90, 91, 92 and 93, 1G3, How are the joints lubri-
cated?

AXD PHYSIOLOGY.

73

merits which unite the lower
end of the fibula to the tibia
and the tarsal bones, and in
Fig. 93 the ligaments of the
foot.

1G3. Synovial Membrane
and its Secretion. — The
lubrication of the joints is
effected by means of a thin
membrane lining their cavi-
ties which secretes an oily
substance called the Synovia,
(Fig. 94, p. 74), that is con-
stantly applied to the oppos-
ing surfaces. In health the
action of the joint stimulates
this membrane to the secre-
tion of a proper amount of

Fig.

Fig. 92.

A Posterior View of the Ankle-Joint of
the Left Side. 1, The Interosseous Liga-
ment of the Bones of the Leg. 2, The
Posterior Inferior Ligament connecting
the Tibia and Fibula. 3, The Transverse,
or Long Fibres of the same Ligament

4, The Internal Lateral Ligament. 5, Tho
Posterior Fasciculus of the External Lat-
eral Ligament. 6, The Middle Fascicu-
lus of the same. 7, The Synovial Capsule

5, The Os Calcis.

A Vertical Section of the Ankle-Joint and Foot of the Eight Side. 1, The Tibia.
2, The Astragalus. 3, Os Calcis. 4, The Scaphoides. 5, The Cuneiforme Internum.
G, Tha Metatarsal Bone of the Great Toe. 7. Tho First Phalanx of the Great Toe.
8, The Second Phalanx of the Givat Toe. 9, The Articular Cavity between the Tibia
and Astragalus, Avitli its ArticuLir Adipose Matter. 10, Tlio. Synovial C";;psule between
the Astragalus and Calcis. 11, The (Jalcaneo-Astragalian Interosseous Ligament.
12, The Synovial Capsule Ijetwocn the Astragalus anl Scaphoides. 13, The Calcaneo-
Scaphoid Ligament. 14, The Caloaneo-Cuboid Ligament. 15, The Synovial Cipsule
between the Scaphoides and Cuneiforme Internum. 16, The Synovial Capsule between
the Cuneiforme Internum and the First Metatarsal Bone. 17, The Metatarso-Pha.
langial Articulation of the Great Toe, with the Sesamoid Bones below. 18. The Pha-
langial Articulation of the Great Toe.

u

HITCHCOCK'S AXATOMY

Fig. 94.

An Internal View of the Ankle- Joint of
the Right Side. 1, Internal Malk-olus.
2, 2, Part of the Astragalus, the rest being
concealed by Ligaments. 3, Os Calcis. 4,
Scaphoides. 5, Internal Ciinc^ifonn Bone.
G, Internal Lateral, or Deltoid Ligament.
7. Tiie Synovial Capsule, covered by a few

Fibres of a Capsular Ligament. S, Tendo Achillis. A small Bursa is seen
between this Tendon and the Tuberosity of the Os Calcis.

synovia, the superabundance
of which (when it is present)
is removed bj the absorb-
ent vessels. This lubricating
fluid, however, is not poured
out directly upon the ends
of the bones, but upon smooth
and elastic cartilage, which
is found in every joint, not
only for furnishing a smooth
articular surface, but also to
diminish the force of jars by
its elastic character.

FUNCTIONS OB, USES OF THE BONES.

164. The uses of the bones may be classed under three
divisions :

First, for a framework to the whole system.
Second, to furnish points of attachment to muscles and
ligaments.

Third, to protect the softer parts.

165. A Framework. Ligaments used as Braces and Pins.
— Exactly as a human architect plans and constructs a frame
to the house, so the Great Architect has formed the bones.
Each bone is fitted exactly to the position, size, and use of
the part where it is placed, and nowhere can a supernumerary
bone be found. In the house to be built, braces and joining
pins must be employed, and those generally of a tougher
material than the frame itself So in the human body, liga-

Why i3 cartilage ll^^e^;.l in the lubrication of joints? 1G4. Give the uses of the bones
03 classed above. 165. Com4>a.3 tho bonea and ligaments with the timbers, brac«s and
pina of a houM.

ANDPHTSIOLOGY. 7q

ments and cartilage exist wherever two opposite extremities
need strength and support to keep them in their places. In
the railway locomotive immense strength is required, and at
the same time perfect freedom of motion in certain positions,
all of which is effected bj the ponderous bars, levers and
wheels, perfectly secured by bolts, keys and screws. But in
the human frame by how much more simple means is the
same end secured. No angular or cylindrical couplings
secure the human joints, though beautifully adapted to pro-
duce movement in every direction, and no attention or care is
necessary to lubricate and preserve in good condition tho
working parts of this machine, but a fcAV tough fibers and
membranes, secure at once in a most perfect manner every
portion of the frame, and provide at the same time means for
its lubrication.

166. Use of the Anomalous Forms of Bones. — The bones
are fitted for the attachment of muscles and ligaments.
Hence it is that they are of such anomalous and curi-
ous forms, apparently constructed without design or pur-
pose. But as we study them, and understand the various
motions which they must perform, as well as the organs
which many of them must protect, or provide space for, we
find that it is impossible to improve in the slightest degree on
the construction of the skeleton. The size, the form, the
quality of material, the exact position of every process, curve
and foramen of the bones, and the manner in which all are
arranged, are most wisely adapted to their functions and to
the happiness of the vertebrated race.

167. Reason why the Long Bones are Tubes. — In this
connection should be mentioned the reason why the long
bones are hollow. It is for the same cause that the stems of
grasses, grains, and many other vegetables are hollow cylin-
ders, instead of solid rods : to secure great strength with as

166. Why are the bones of such peculiar shapes? 167. Give tho reason why many of
tlio bones arc hollow.

^Q HITCHCOCK'S ANATOMY

little material as possible. For example, were the Imman
femur a solid rod, instead of a hollow cylinder, as it now is,
it would require a bone twice the diameter of the present one
tj be sufficiently strong for the purposes required of it.
Hence were the whole skeleton constructed on this principle,
it would be so cumbersome and heavy that it would require a
larger amount of muscle, making the body unwieldy, and
thus deprive it of its rapid and easy motion.

168. Protection given to the Brain. Use of the Diploe*
Reason for several Bones in the Skull — The bones af-
ford much protection to all the enclosed and adjacent or-
gans. In the bones of the head, for example, how perfect
the guard over the nervous center. Here are three means
for protection, two plates of bone, and an intervening cel-
lular space. The outer table being very tough presents
a substance somewhat yielding to blows inflicted by pointed
substances, and even if the blow be so severe as to cause
fracture, this can not extend so far as in a hard and
brittle material. And the intervening space or diploe very
materially deadens the force of any shock given to the
outside of the head, precisely as the springs of a carriage
j)revent the unevenness of the road from giving the same
sudden jolt to the body that is communicated to the wheels.
The inner table is necessarily brittle, since the brain de-
mands the firmest possible support. But why is the skull
made up of several bones instead of one ? In the first place a
more symmetrical growth can be effected, provided the points
of increase are numerous, and especially so since in early life,
while the growth is going on, there is a thin layer of cartilage
between the edges of each bone, thus allowing all necessary
motion; secondly, because a fracture can not extend furthei
than a suture, as all the vibrations are overcome by the inter-
position of any soft substance like cartilage. And for this

1C3. IIow do the bones afford a protection to the softer parts? What is tho
•use of the dipluii in tho bones of the skull ? State the reason of several bones in
the Bkull.

AND PnYSIOLOGY. 7?

reason the jar of any blow is greatly lessened by the same
cause.

169. Use of the Ribs. — Again we see the bones of the
thorax arranged for the protection of the enclosed organs.
Within this cavity are organs delicate and easily destroyed,
but which require elastic and movable walls. The elasticity
is easily gained by the cartilaginous portion of the ribs at-
tached to the sternum, which yields considerably upon pres-
sure ; and the motion and consequent enlargement is effected
by the oblique position of the ribs, as they run downwards
and forwards from their articulation with the vertebrae. As
the vertebral extremity is the fixed point, of course the eleva-
tion of the sternal end will enlarge the cavity of the thorax
antero-posteriorly. Another use of the cartilaginous extrem-
ity of the ribs is to lessen the chance of fracture. The tho-
rax is exposed to blows and falls more than many other por-
tions of the body, and therefore more exposed to fracture.
For instance, if a person suddenly falls to the ground, the
head by an instinctive movement is raised, while the trunk or
extremities receive the force of the shock. Also the head or
extremities can by rapid movements be suddenly removed
from the contact Avith missiles, while the body, comparatively
unwieldy, must meet the blow.

170. Use of tlie Iiiiiominata. — The expanded condition
of the Innominatum affords service and protection in different
ways. A depression, or cup-shaped cavity is thus made for
giving a firm support to the organs contained in the abdomen,
as well as a solid foundation to the spinal column. It how-
ever renders especial service by furnishing a powerful point
of attaehment for many of the muscles both above and below :
those which form the walls of the abdomen, and many of
those which move the extremities.

171. Why there are so many Bones in the Spinal

169. Describe the uses of the ribs, and the reason why they are partly made up of car.
tilage. Why do thoy x-un obliquely from the points of attachment? 170. Explaia wliy
the Innominata are so broadly expanded.

78 HITCHCOCK'S anatomy

Column, — A large number of bones in the spinal column is
necessary in order to give flexibility to the body. Were the
number considerably less, the movements of the trunk would
be attended with much more dijEculty than at present, and be
devoid of grace. And were the separated vertebrae long
bones, they would be much more easily broken, thereby en-
dangering the spinal marrow. Another reason for the great
number of these bones, is the necessity of the elastic cartilage
between them, to protect the brain. Were the joints fewer,
in order to give equal protection to the brain from jars, this
cartilage must of necessity have been greatly thickened,
thereby weakening the joint, and injuring it as a central axis
of support to the whole body, and also increasing the liabil-
ity to dislocations, as well as greatly endangering life, by
pressure upon the spinal cord.

172. Use of the Clavicle. — The value of the clavicle lies
in keeping the upper extremity in its proper position, so as
to prevent the humerus from coming forward towards the
middle portion of the body. By its direct resistance it also
assists in some muscular actions, such as lifting heavy weights
with the hands.

173. Need of two Bones in the Fore -Arm. — The use of
two bones in the fore-arm, as already mentioned, is to pro-
duce the movements of supination and pronation. And since
these movements are of primary importance, and one bone
can not answer this end, two are provided. Again, if one be
fractured, the other will act as a splint for keeping the broken
one in place, greatly superior to the artificial splint, because the
natural splint needs no compression.

174. Why several Bones in the Carpus. — In the carpus
are found eight bones, and yet we know there is but little
motion between them. The reason why exactly this number

171, What is the reason why so many bones are placed in the spinal column ? What
is the use of the intervertebral substance? 172. What service floes the clavicle render
to the upper extremities? 173. Why are there two bones in the fore-arm? 174. What
can be said of the many bones of the carpus ?

AND PHYSIOLOGY. 79

is required, is not so easily explained, but it is evident that
one bone could not perform their function, nor the prolono-a-
tion of the radius and ulna to the metacarpus. Several bones
are required in order to give easy and graceful motion to the
wrist, as well as strength. One bone could not answer the
purpose, since the very many offices, which the hand has to
perform, could not be effected, unless the wrist bones were
very strongly bound together, and flexible to a certain extent.
The arrangement of the bones in two rows allows a little
movement of the hand upon the wrist.

175. Function of Metacarpus. — The metacarpus of five
long bones gives support to the fingers. They are long rather
than short bones, in order to give slenderness to the hand,
and also to afford a solid surface for the fingers to meet in
the act of prehension.

176. Need of three Phalanges to the Fingers, and two
Phalanges to the Thumh. — The phalanges of each finger are
three in number, whilst those of the thumb are but two.
The obvious reason of this is to give greater firmness to the
thumb, and flexibility to the fingers. The hand in man dif-
fers from the anterior extremity of all other animals in the
power of perfectly opposing the thumb to each of the fingers,
which of course gives him a great superiority in all delicate
manipulations, and especially in grasping minute objects.
And it is easy to see that a third phalanx in the thumb would
not only diminish the firmness of this member, but would
render the hand an awkward and clumsy organ, instead of an
instrument beautifully and perfectly adapted to the multi-
farious offices which it has to perform.

177. The great Length of the lower Extremities. Pe-
culiarities of the Femur. — The value of the great length in
the lower extremities, is manifest as a means of rapid pro-

Why would not ono bono bo sufiicient? 1T5. The use of the metacarpus. 176. Why
are there but two phalanges in the thumb and three in each finger? What would bo
the effect of a third phalanx in the tkumb ? 177. Why are the lower estrcmities pro*
portionally longer than tho upper ?

4*

80 • HITCHCOCK'S ANATOMY

gression, and also for affording a firm support to the trunk
when engaged in the various kinds of labor. Were these ex-
tremities much shorter than they now are, walking would not
only be a tediously slow process, but a laborious one. The
femur has some remarkable peculiarities. In the first place
it presents in its articulation with the innominatum the most
perfect specimen of a ball and socket joint in the system.
Besides this it bends at nearly a right angle at its upper end,
making what is called the neck, and here it is that the frac-
ture of the thigh-bone generally occurs. The use of this
curvature is to place the points of support for the trunk as
far as possible from the center of gravity of the body, thereby
giving the body the most secure position on the lower ex-
tremities, and especially for the attachment of powerful
muscles to move the thigh and leg, as well as to maintain
securely the trunk when the legs are the fixed points. This
projection is called the Trochanter process, and is spongy or
cellular in its structure. And it is not a little interesting to
notice, when this process is sawn through in a perpendicular
direction, that the cells are arranged in an arched form from
below upwards, thereby greatly aiding the strength of the
bone. The same arrangement is seen in some other bones of
the body, when they are in an exposed position. The lower
extremity of this bone, as has already been mentioned, is
greatly expanded, in the shape of two condyles for the firm
articulation with the tibia. The necessity for this lies in the
fact that the knee-joint h one of the most exposed joints in
the whole body, and the one which receives the hardest strain.
The protection of the nerves and blood vessels, which are sent
to the leg, is also worthy of a notice. It is effected by a
deep groove between the condyles on the backside of the
leg, which guards these vessels from blows in every direc-
tion except behind, from whence they are the least apt to cotoe.

What remarkable joint between th© femur and the innominata? What is the ar-
rangement of the cellular structure in the upper part of the femur? Why has the fe-
mur so largo processes on its lower extremity ?

AND PHYSIOLOGY. 81

178. Use of the Tarsus . — In the Tarsus we see the value
of several bones instead of one. It is the movement of these
upon one another that imparts elasticity to the step and firm-
ness of support to the whole bodj ; and hence it is that all
artificial legs produce a limping motion in the body. By no
mechanical contrivance can the suppleness of the tarsus and
of the muscular actions be supplied.

179, Two Bones in the Great Toe, and tln-ee Bones
in all the Others . — The great toe of the foot, like the thumb
of the hand, has only two phalanges. This is mainly for the
purpose of securing greater strength to the foot in walking
and standing. It is also of service for opposition to the other
toes, as is seen in those rare cases of persons deprived of their
upper extremities, who can readily make use of the foot for
many of the delicate purposes to which the hand is adapted,
such as writing, using scissors, and placing the crystal in a
watch. The remaining toes, like four of tlie fingers, receive
a tendon only at the base of the second and third phalanx,
the first one being interposed merely to give strength and
slenderness to the extremities, as well as the power of sur-
rounding objects in the act of prehension. The slenderness
of the fingers above the toes is a distinguishing characteristic
of man, showing that the office of the foot is merely to sup-
port the body on the ground, and of the hand to perform the
business of every-day fife in its ten thousand forms.

HYaiENIC INFERENCES.

180. — 1. Reason of Distorted Bones.— In the early life
of man and other vertebrate animals, the animal portion of
bones greatly predominates over the earthy constituents, and
hence they yield more readily to pressure, but are not so

ITS. How do the l)oncs of the Tarsns give elasticity to the step? 179. How do tho
phalanges of the f(X)t compare ivith those of tho hand in number? Why are the hones of
the hand longer than those of the foot ? JSO. What kind of matter predominates in the
early life of bones ?

82 HITCHCOCK'S a ^^ atomy

liable to break as in older persons. This is tbe reason why
falls and blows so seldom do much injury to children. It is
also the reason why distortions and curvatures of some of the
bones are so common, since too often children are either urged
or permitted to use their limbs excessively before their bones
are made solid by the deposition of earthy matter. These
distortions are most common in children who are weak and
sickly, because in them the recuperative powers are small.

181. — 2. Danger of Constrained and Unnatural Posi-
tions in Children,— Hence we infer that children should
not be confined in any unnatural or constrained position, but
allowed to move freely in whatever direction nature may de-
mand. And all punishments of this sort, inflicted by parents,
guardians, and school teachers upon young persons, such as
standing on one leg, or holding a book with a,n extended arm
for a long time, are dangerous and ought to be proscribed,
since they are too often the cause of bow legs and curvature
of the spinal column.

182. — 3. Canse of the Rickets. — The disease known as
Rickets is produced by imperfect nutrition of the bones. Thifj
is generally, though not always, the result of poverty or vice,
or both combined. The direct cause of the disease is a de-
ficiency of earthy matter in the bones. This is either ab-
sorbed or never produced, and as a result the bone is softened,
and by the tonicity of the muscles the body is drawn into un^
sightly deformity. An observance of the laws of health is
the best medicine for this disease.

183.~4. Need of Cleanliness of the Teeth— Tooth Pow-
ders—Tooth Picks— Decayed Teeth — Worthless Teeth
j-;honld he Extracted . — From the almost inevitable exposure
of the teeth to mechanical and chemical agen^s, we see that
they need considerable care and attention. They need to he

Why do falls an<l blows scldnm injure children as they do adults? In what children
are distortions the most common ? ISl. Why should children hu unconstraim-d in their
bodily exercise ? Wliat is said about punishments that distort the bones of children ?
1S3. What is the usual cause of Eickets? What is the best medicine for it? 1S3. Give
the most important hygienic rule for the preservation of the teetb.

AND PHYSIOLOGY. 83

ke-pt dean. This can ordinarily be accomplished bj the use
of a soft tooth brush and pure water thoroughly applied at
least once in the twenty-four hours. A tooth-powder of an
alkaline character, or, what is the same thing, clean toilet
soap, can be occasionally used with benefit. A tooth pick
should be possessed and used by every gentleman and lady
toOj though it should be made of wood, ivory, tortoise-shell,
bone, quill, or some substance softer than the tooth itself If
the teeth are very closely set together, frequently drawing a
thread between them will aid in preventing decay. If any of
them have begun to decay, a good dentist should be consulted
as soon as possible, and the cavities filled with gold, since ar-
tificial teeth can never be so valuable as natural ones, even
though partly filled with gold. When teeth are past filling
they should be removed, as they are the means of producing
decay in others, as well as many pains called neuralgia.

184.— 5. The Teeth not to be Used on very Hard Sub-
stances . — The teeth should be used only for the purposes for
which they vfere designed. The teeth of squirrels, rats, and
beavers were made expressly for cutting wood and gnawing
open nuts, but not so with the human teeth. Even the con-
stant biting of thread, the holding of a pencil or tobacco-pipe
between the teeth, and especially the cracking of nuts, are
practices very injurious, and often cause the decay of these
organs.

185.— 6. Teeth Generally Decay Early in Life.— Ex-
perience shows that teeth decay the most rapidly in the early
part of life, generally between the ages of fifteen and
thirty. Hence youth need to take especial care to preserve
them, not only on account of the pain and deformity which
their loss occasions, but because of their remote efie^ts upon
the voice and especially upon the digestive organs.

What kind of tooth powder is the best ? Who should use tooth pic^s ? What treat-
in<?nt &h<)uM be given to decaying and decayed teeth? What substance alone should
teeth be filled with ? 184. For what purposes shouM human teetli never be used? 1S5.
In what period of life do teeth decay the lusttst ? What aro iunKU'tant reasons for au
especial core of the teeth ? •

84 Hitchcock's anatomy

186. Classification of Animals. — The highest and most
competent authorities differ widelj in their attempts to classify
the Animal Kingdom ; that is, to divide it into smaller groups,
which are Sub- Kingdoms or Provinces, Classes. Orders, Fa-
milies, Genera, and Species. We have no room, had we the
ability, to decide these difficult questions. There is, how-
ever, a general acquiescence in the principle first introduced
by Cuvier, that animals were created on four great types or
plans, which he calls Vertebrata, Articulata, Mollusca, and
Radiata. The discrepancy lies chiefly in the subdivisions of
these leading groups. We shall merely present the classifi-
cations of two of the most eminent livinor anatomists and zoolo-

o

gists — Professor Louis Agassiz of Cambridge, and Sir Richard
Owen of London — not attempting to decide between them.

187. Agassiz divides the whole animal kingdom into four great branches,
the same as those named above. The Vertebrata he divides into eight
classes: 1, The Myzontes, subdivided into two orders; 2, Fishes proper,
into two orders ; 3, Ganoids, into three orders ; 4, Selachians, into three or-
ders; 5, Amphibians, into three orders; 6, Reptiles, into four orders; T,
Birds, into four orders ; 8, Mammalia, into three orders.

The Branch Articulata he divides into three classes : 1, Worms, with three
orders ; 2, Crustacea, with four orders ; 3, Insects, with three orders.

The Branch Mollusca he divides into three classes: 1, Acephala, with
four orders; 2, Gasteropoda, with three orders; 3, Cephalopoda, with two
orders.

The Branch Radiata ho divides into three classes: 1, Polj'pi, with two
orders; 2, Acalephae, with three orders; 3 Echinoderms, with four orders.

188. Owen calls the above-named four divisions of the Animal Kingdom,
Provinces. The Province Vertebrata he subdivides into four classes: 1, Mam-
malia, with fifteen orders; 2, Aves, or Birds; 3, Eeptilia, with fifteen orders;
4, Fishes, with eleven orders. His fifteen orders of Mammalia are: 1, Mono-
tremata; 2, Marsupialia; 3, Rodentia; 4, Insectivora; 5, Cheiroptera; 6,
Bruta; 7, Cetacea; 8, Sirenia; 9, Toxodontia; 10, Proboscidea; 11, Peris-
sodactyla; 12, Artiodactyla; 13, Carnivora; 14, Quadrumana; 15, Bimana.

The Province Articulata he divides into six classes : 1, Arachnida, with
four orders ; 2, Insects, with eleven orders ; 3, Crustacea, with eleven orders ;
4, E^izoa, with three orders; .5, Anellata,. with four orders; 6 Cirrj_pediaj
with three orders.

The Mollusca he divides into six classes: 1, Cephalopoda, with two orders;
2, Gasteropoda, with ten orders ; 3, Pteropoda, with two orders ; 4, Lamelli-
branchiata, with two orders ; 5, Brachiopoda ; 6, Tunicata, with two orders.

A K D P H Y S I O L O a Y . B5\

The Radiata lie divides into nine classes: 1, Echinodermata ; 2, Brjozoa;
3, Anthozoa; 4, Acalephas; 5, Hydrczoa ; 6, Coelelaiintlia ; 7, Sterelmintha ;
8, Eotifera; 9, Polygastria.

- 1 89. To the above Animal Kingdom Pro£ Owen has added another kingdom oi
organisms, " mostly of minute size, and retaining the form of nucleated cells,
w^iich manifest the common organic characters, but without the distinctive
Kuperadditions of true plants or animals." These he calls Protozoa, and ar-
fanges in three classes: 1, The Amorphozoa, or Sponges; 2, the Rhizopoda^
which are the Polythalamia, or Foraminifera ; 3, the Infusoria, or Animalcula
/-the last two classes being mostly microscopic.

COMPARATIVE OSTEOLOGY.

191. Microscopic Structure. — In microscopic structure and
c^^mical composition the bones of mammals, including man,
and of all vertebrates are essentially the same, and in their
general outline a considerable degree of correspondence can
be traced between many of the bones of the human system,
and those performing similar functions in the lower animals.
Thus we almost always find the femur to have a globular
head on its upper extremity supported by a neck which makes
a considerable angle with the shaft, and the tAvo large con-
dyles on the lower extremity.

192. Spinal Coluraii of Mammals. Cervical, Dorsal,
Lumbar, Sacral, Caudal Yertebrse. — In Mammals the Spinal
Column is made up of five classes of vertebrae : the cervical,
of the neck ; the dorsal, of the back ; the lumbar, of the loins ;
the sacral, of the hip ; and the caudal, of the tail. The Cervi-
cal vertebrae, with but two or three exceptions in all mammals,
consists of seven in number. The average number of the Dor-
sal is thirteen, the Bats having eleven, and one of the Sloths

191. What Is the microscopic structure of the bones of Mammals ? What about the
general correspondence in outline, etc. ? Instance the femur. 1^2. What' are the five
classes of VertebrfB ? How constant is the typical number seven for the Cervical ver-
tcbraj ? Give the average number of the Dorsal.

86

HITCHCOCK'S ANATOMY

Skeleton of the Camel, v. c. Cervical Vertebrae, v. d. Dorsal Yortebrje. v. I. Lum-
bar Vertebrae, v. s. Sacral Vertebrse. v. q. Caudal Vertebrae, o. Scapula, h. Hume-
rus, c. Ribs. cu. Ulna. ca. Carpus, in. c. Metacarpus, ph. Phalanges, fe. Femur,
ro. Patella, ti. Tibia, ta. Tarsus, m, t. Metatarsus, cl. Clavicle.

Fig. 96.

Skeleton of Bat The descriptive letters arc the samo as iu Fig. 0.1

twenty-three. The Lumbar are usually the largest in size,
and their range is from two to nine. The Sacral consist

AND PHYSIOLOGY.

67

usually of four, but vary from one to nine, and as in man,
are almost always consolidated. The Caudal vary exceed-
ingly in number, sometimes amounting to forty-six. When
of this number, they gradually dwindle away towards the ex-
tremity of the tail, and lose the characteristics of vertebrae,
and become mere ossicles or bits of bone.

193. On what Length of Neck depends.^Hence we see
that the length of the neck in quadrupeds does not depend
on the number, but on the length of vertebrae, since the Cam-
eleopard (Fig. 97),

Fio. 97.

Skeleton of Cameleopard. C Cervical VertebrtD. D. Dorsal Vertebra;. L. Lumbar
Vertebrae. S. Sacral Vertebrre. cd. Caudal Vertebraj. 51. Scapula. 53. Humerua.
54. Ulna. 55. Kadius. 56, Carpal Bones, 57. Metacarpus. Hi, and iv. Phalanges, 62. Inno-
minatum. 64 and 65. Femur. 66^ Patella. 66. Tibia. 67 and 6S. Tarsus. 69. Metatartaa.

S8

HITCHCOCK'S ANATOMY

which has the longest neck, has only seven cervical vertebrae,
the same number with the Mole (Fig. 98), an animal with

Fig.

Skeleton of the Mole. The illustrative Figures represent the same as in Fig. 97.

one of the shortest necks among quadrupeds, Cuvier states
that in general the length of the neck is such, that, added to
the head, the length of both is equal to the height of the ani-
mal's shoulders above the ground. If this were not the case,
grazing animals could not reach their food, nor any quadru-
peds their drink without bending the legs.

194. Shape of Body. — The shape of the body of quadru-
peds, whether slender, or short and thick, depends on the
number and size of the Lumbar and Dorsal vertebrae.

195. Boiics of Skull. Elepliaiil's Head. Styloid, and
Tympanic Bones. — The general arrangement of the bones
of the skull, as well as their number, corresponds very nearly
with those of man. The two Parietals are usually small
bones, and sometimes united into one. This is true of the
Horse and the Bats. In the Hog and Rhinoceros the two
parietal bones are united in one, while their frontal bone is

What peculiarity about Lumbar? What of the Sacral ? How large a number of Sa-
cral .are sometimes found ? 190. Upon what does the length of neck in quadrupeds de-
pend on ? Instance the Giraffe and Mole. What is the general rule about tlie length of
the neck? 194. What does the shape of the body mainly depend on? 195. How do
the Parietals sometimes differ from man?

AND PHYSIOLOGY. 80

^im

Sknll of Horse, oc, t., f. Occipital, Temporal, and Frontal Bones, n., m., im.
and mi.. Nasal, Superior Maxillary, Intermaxillary, and Mandibular Bones, o. Orbit.
i. Incisive Teeth, mo. Molar Teeth.

in two pieces. In nearly all the orders of mammalia this
bone (the frontal) is always found in two pieces. In the
Elephant the bones of the cranium are all united into one
at an early period in life, forming but one piece, in order
probably to make it sufficiently strong to support the great
weight which is brought upon these bones by the tusks
and proboscis. The Styloid process of the temporal bone
is usually in mammals a separate ossicle. The bone which
contains the organ of hearing in all mammals, except
man and the Apes, is a separate bone called the Tympanic,
and is not simply the petrous portion of the temporal as in
man.

196. Bones of Face, Iiitermaxillarics, Lower Jaw. —
In the Face too the bones correspond very nearly with those
in man. The essential difference is found in the upper jaw.
Instead of the two superior maxillaries meeting each other on
the median line of the body in front, there are two other bones
between them called the Intermaxillaries. These are very
conspicuous in animals provided with large canine teeth, or
tusks, as the Elephant and Squirrel. The Lower Jaw in

What peculiarity about the bones of the Elephant's skull? What bone is -wanting in
the Whale? Describe the Tympanic Bone. 196. In what respect do the bones of the
face in Mammals differ from those in man ? Where are the Intermaxillaries ?

r90 HITCHCOCK'S ANATOMY

quadrupeds generally consists of two pieces, the division being
made on the median line of the body. In the Hog, Horse
and Cow it consists of a single bone. In the Greenland
Whale it is in its simplest form, which is that of two arched
ribs.

197. Form of Skull, of Oraiig Outangs. — Viewed as a
"whole the form of the skull departs most from that of man in
the lowest orders. In the Ornithorjnchus the face is pro-
longed into a beak or bill, and in the Horse the facial por-
tion of the head is four times larger than the cranial, exactly
the reverse of the case in man. In the young Orang Outangs
the form of the skull very closely resembles that of man, and
in the adult the size of the exterior of the cranium nearly
equals that of man, though its capacity is considerably le:s.

198. Teeth of (Jaadrupcds, Carnivorous, Herbivorous,
Insectivorous and Barbed Teeth. — The Teeth of Mammals
vary exceedingly. They may, however, be classed under the two
divisions of flesh and vegetable eating, according to the food
of the animal. Those made to live on meat are sharp and

pointed, for simply tearing the flesh
Fig. 100. into such small portions that it

can be swallowed, while those eat-
ing herbs and grass, have the front
" teeth with sharp edges like that
of a knife for cropping the food,
and back teeth with flat surfaces,
or vertical ridges of enamel in-
terspersed between the ivory or
dentine, which act the same
part when brought together with

Teeth ofaLion (Carnivorous Animal) a lateral motioU, aS do the Upper

What of the Lower Jaw ? 197. In what orders docs the head differ most from that of
jnan? How does the skull of the Orang Outang differ from thnt of man? lOS. What
are the two l^inds of teeth among mammals? Describe each. Give the reason why th©
teeth are furnished as they are.

AND PUYSIOLOGY. 91

Fig. 101. Fig. 102.

Teeth of an Herbivorous Animal. Teetli of an Insectivorous Animal.

and nether millstone for grinding grain. Thoso which live
upon small insects have conical teeth with corresponding de-
pressions in the opposite jaw in order to crush the skeletons
and envelops of their prey. The Seals, which live on Fish^
are provided with barblike appendages similar to those on fish-
hooks, in order that they may hold their slippery prey.

199. Humerus, in Burrowing Animals. — The Humerus
is generally a long cylindrical tube, with a large rounded
head at its upper extremity. But in swimming and burrow-
ing animals it is a short and curved bone, with each extrem-
ity very much modified for the attachment of muscles, since
the fore- legs of such animals need to be used with great fre-
quency and force.

200. Bones of Fore-Arm. Carpus, Metacarpus, Pha-
langes.— The element in which mammals live, greatly modi-
fies the bones of the fore-arm and hand. (Fig. 103, p. 92.)
In general there are two bones in the fore-arm, and but few
animals have the power to move these one upon another like
man. The Carpus is constantly made up of two rows, though
not of the same number. They vary from five to eleven. The
Metacarpus consists of five elongated bones for the most part.
But these are three in the Rhinoceros, and one with two

What is remarkable about the teeth of the Seal ? 199. What is tlie general outline of
the Humerus? In what animals is it modifierl ? 200. What cflFect has the element, in
which animals live, upon tlie anterior extremities ? How do the Carpal Bones range ia
cumber ? What are the caceptioQs to the typical number five uf the Metacarpus ?

92

HITCHCOCK'S ANATOMY

Anterior Members of different Animals. A. Fish. £. Bird, C. Dolpbin. D. Doer.
M Bat. F. Man.

rudimentary bones in the Horse. From one to five fingers are
usually found, of which the thumb is generally rudimentary,

Fig. 104. Fig. 105.

IK

— /a

Hind Foot of Horse, t. Tibia, ia. and
ta\ Tarsus, c. Metatarsus or Canon Bone.
«. Rudlmtintary Bone, p., pi., and pt.,
first, second and tbh\l Phalangci.

- tt

[-:- pi

Foot of Stag. (Kepresentative let-
ters tba same as in the last figure.)

ANDPHYSIOLOGT, 92

consisting only of a single bone. The Elephant has five toes,
the Hocf four, the Rhinoceros three, the Cow two. and the
Horse one. Sometimes the longest finger (paddle) of the
"Whale contains eleven bones. In burrowing and swimming
animals the fore-feet are generally the largest, and among some
quadrupeds the reverse is the case. The posterior extremities
of quadrupeds are usually less modified than the anterior ones,
as they are used mainly for support and progression.

OSTEOLOGY OF BIRDS.

201. Vei'tebrffi, Cervical, Dorsal, Caudal. — Birds exhibit
several peculiarities in their Spinal Column. The number
of Cervical Vertebrae is much greater than in mammals,
giving them long and flexible necks. (Fig. 106, p. 94.)
The number is between ten and fifteen, but the white Swan
has twenty-three. The Dorsal Vertebrae vary in number
from seven to nine, and admit of but little motion upon
each other, many of them being frequently anchylosed to-
gether, as in the human sacrum. (Fig. 107, p. 95.) The
design of this is to give the firmest point of attachment to
wings that can be secured. The Caudal Vertebrae are hol-
low and form a complete canal for the spinal marrow. The
last one has a large disc-shaped process upon it for the sup-
port of the long feathers of the tail.

202. Bones of Head, Os ([aadratum, Jngr.l Eone. —
The bones of the head correspond in number and position
for the most part with thos3 of the mammalia. (Fig. 108,
p. 95.) They are, however, united together at a very early
period, and the sutures can not be recognized except in very
young subjects. One point of difference between these skulls

What are so!ne modifications of Phalanges? 201. Coinpare the Cervical Vertebrje ol
Mammals ^vit]l those of Birds. What number of Cervical Vertebr.-e has the Swan? Why
are the Dorsal Vertebnc usually firmly fixed together? What peculiarity of the Caudal
Vortobra?? 202. AVhat can be said of the Sutures in the head of birds ?

91

HITCHCOCK'S ANATOMY
Fig. 106.

Skeleton of Swan. C. C. Cervical VertebrcR. D. D. Dorsal Yevtebra?. S. S. Sacral
7ertebra}. cd. Caudal VertebifE. 51. Scapula. 52. Coracoid Bone. 53. Humerus. 64
»n(l 55. Pwadius and Ulna. 56. Carpus. 57. Metacarpus. 58. Furcula. 62. Innominata.
63. Sacrum. 6-i. Pubis. 65. .Femur. 63. Tibia. 63'. Pattilla. 67. Fibula. C9. Tarso
Matatarsus. »., «7., ilL, its. Phalanges.

AND PHYSIOLOGY.
FlO. 107.

95

Cervical Vertebra.

Coccyx.

Tibia.

Tarsoa.

Clavicle or Furcola.
Sternum.

-., Phalange.

Skeleton of the Gotland.

and those of the mammals is that the occipital bone con-
sists of four parts instead of one. A small bone, too, is al-
ways present called the Os Quadratum, in close proximity
with the occipital,^ temporal, and maxillary bones. A Jugal

Lachrymal Boue<
Nostril. \

iup. Mazil<

Fig. 108.

Orbit. Inter-Oibitar Septum.

Cranium.

Tymr r.num.

Os Quadratum.

Nasal Fossse. Jneal Bone. Infer. Maxil.
Heail of the Eagle.

What bone in the skull of birds that demands attention?
5

96

HITCHCOCK'S ANATOMY

Bone is also found which is similar in position to the zygo-
matic process of the temporal bone in man.

203. Bill. — Teeth are entirely wanting in Birds, their
place being supplied by a single horny projection on each jaw
known as the Bill. Teeth are not needed by these animals,
since mastication, where it is necessary that it should be per-
formed, is done by the gizzard.

204. Ribs. — The Ribs are very firmly articulated with the
sternum by bone and not cartilage, so that they have a ten-
dency to keep the thorax as fully distended as possible all
the time, which is its natural position.

Fig. 109.

205. Sternum, in what

Birds largest. — The Ster-
num is the most striking of
all the bones in a bird. It
is the largest bone in their
bodies, a flattened and some-
times quadrangular bone, hav-
ing upon its anterior surface
a prominent ridge like the
keel of a ship, for the attach-
ment of the pectoral muscles
used in flight. The size ol
this ridge generally stands in
direct relation to the powers
of rapid flight, and hence in
the Humming Bird, one of the swiftest on the wing, it is
proportionally the largest.

206. Clavicles, Coracoitl Bone.— The Clavicles of birds
present a marked peculiarity. They both unite at their an-
terior extremity, forming a forked bone known as the Fur-

203. What servos tho purpose of teeth for Birds ? 204. How does the articulation of
the ribs affect the condition of the chest? 205. Whicli is the largest bone in birds?
How may we know the powers of flight in a bird by the keel of tho Sternum ? 206. What
do the clavicles of birds form as they are united together?

Bones of Sternum and Shoulder of
Birds, s. The Sternum, e. Notch of tho
Sternum, co. Origin of the Sternal Eibs.
b. Crest. / Fourchette. c. Coracoid Cla-
vicle. 0. Scapula.

AND PHYSIOLOGY. 9t

cula, merry thought, or wish bone. Thej also possess another
bone which acts the part of a clavicle, called the Coracoid.
It reaches from the scapula to the sternum, side by side with
the Fureula, and is a principal source of support to the
wings in flight. There is a bone analogous to this among
some reptiles.

207. Humerus. — The Humerus is generally a larger and
stouter bone than the femur, contrary to the relative propor-
tion in man. This is because the anterior extremities of birds
are of much more importance in their habits than the poste-
rior ones, since the hind legs in most of the flying birds act
merely as a support for 'the body when at rest, and are not of
special service for running or scratching.

208. Bones of Wings, Fingers. — The two bones of the
fore-arm are proportionally longer than the same bones in
mammals, and are longest in birds of flight. The carpus is
represented by two short bones, and the metacarpus is of the
same number. In some birds the thumb is entirely wanting,
but when present it is made up of two bones. The little
finger has only one bone. The middle finger is the longest,
consisting of two and even three bones.

209. Femur, Tarso-Metatarsus, — The Femur is both
thicker and shorter than the bones below it, which constitute
the leg. The Fibula is always, partially at least, united with
the tibia at its lower extremity. The Tarsal and Metatarsal
Bones are found as one, called the Tarso-Metatarsus, which
has at its lower extremity three pully-shaped heads for the
attachment of the toes.

210. Sesamoid Bones . — Sesamoid Bones are abundant in
birds, and in many cases even the tendons themselves become

Is this peculiar to birds alone ? 207. What is the coinparativo length and size of the
Humerus and Fi;nmr in birds? Why are the anterior extremities in most cases tho
kngest? 203. What is said of the two bones of the fore-arm? How many bones are
there in the Carpus? Describe tho fingers of birds. 209. What peculiarities in the
lower extremities of birds? Describe the Tarso Metatarsal Eono. 210. Wliat is said
about Sesamoid Booies i:i birdd?

98 HITCHCOCK'S ANATOMY

considerably ossified. This is especially true of those in
the leg.

211. Birds Bones are hollow.' — The bones of birds are
more or less hollow internally, devoid of marrow, and per-
meated by air. Hence they are provided with openings con-
nected with the respiratory apparatus through which the air is
brought into them. As a general rule the capacity and extent
of these openings throughout the skeleton depends on the size
of the bird, and its powers of flight, since small though rap-
idly flying birds have few hollow bones ; in larger and higher
flying species, however, they are numerous. In the Apteryx
of New Zealand there is the greatest want of these cells. This
bird has no wings, but can run and even burrow in the earth
Yery rapidly. Those bones which convey the air, difier from
all others in appearance by their whiteness and more com-
pactly cancellated or cellular structure.

OSTEOLOGY OF REPTILES.

212. Number of Vertebree in Reptiles. — The Vertebrae
of Reptiles vary exceedingly in number. "For whilst in
the tailless Batrachia only nine or eight cervical vertebrae are
counted, some serpents have full 300." Those of Batrach-
ians have long transverse processes.

213. Ribs; Use of Ribs to Serpents. — ''In the serpents
the ribs are both very numerous and very movable ; where
they cease the tail begins ; here the Caudal vertebrae may be
distinguished from the other vertebrae of the trunk, whilst all
distinction of dorsal and lumbar vertebrae fails." They are

211. Why arc birds' bones usually hollo\7 and more or less occupied by cavities?
212. What is the number of vertebriE in Keptiles? 213. Give the number of ribs in
Reptiles. How do they differ from those of quadrupeds ? Of what service are they to
the animal ?

AND PHYSIOLOGY.

99

valuable instruments of progression, since in many they can
be placed upon the ground and used as feet.

214. Shell of Tortoise. — In the Tortoise that portion
•which is commonly called the shell, is made up of the Cara-

FiG. no.

Skeleton of the Tortoise ; tbo Plastron lias been removed, vc. Cervical YcrtebrcSi
vd. Dorsal Vertebrae, c. Kibs. cs. Sternal Kibs. — The Marginal Bones of tbo Cara.
pace: o. Scapula, el. Collar Bone. co. Coracoid Bone. h. Pelvis. / The Femur.
t. Tibia, p. Fibula.

pace or upper portion, and the Plastron, or lower one. Tho
Carapace seems to bo a mere expansion of the vertebrse, and
the Plastron an expanded sternum. Hence, as the annexed

214. TVhat is tho Carapace and \vliat is the Plastron in the Turtle family ? From what
bones are they developed ?

100 HITCHCOCK'S AX ATOMY

cut shows, the skeleton of the Tortoise is a very simple one,
and the skeleton of the Frog, as shown in Fig. Ill, is
equajlj simple.

215. 11 11 111 cms. — The Humerus of the Tortoise is short
and very much curved. This is made so in order that the
animal may thrust its extremities out of the shell and reach
the ground, which could not be done if the humerus were
straight as it is in most of the other vertebrate animals.

216. Femur. — The Femur is curved in the same animals
for the same reason.

217. Phalanges .—Frogs generally have four fingers, with
from two to four phalanges in each finger. Tortoises and
Lizards generally have five fingers, and from two to five
phalanges in each finger.

Fig. 111.

Skeleton of tho Frog.

OSTEOLOGY OP FISHES.

218. Bony and Cartilaginous Fishes.— The skeletons of
Fishes are of two kinds, those made up of bony, and those of
cartilaginous matter. (Fig. 112.) The microscopic structure
of the scale of a Pike is seen in Fig. 113. Of the former kind

215. Why is the Humerus of the Tortoise curved? 217. How many fingers have
Froths Lizards, and Tortoises? 21S. What are the two kinds of skeletons in Fishes J
Givo examples of each.

AND PHYSIOLOGY.

101

as representatives arc the
Shad and Flounder, and of
the latter, the Shark and
Sturgeon.

219. Two Kinds of Ver-
tebrsB. — The only kinds of
Vertebras in Fishes are the
Dorsal and Caudal. These
vary in number from seven-
teen to more than a hundred.
Their bodies (vertebrae) pre-
sent on both articulating sur-
faces a conical depression which
is filled with a soft matter
having the same use as the
elastic intervertebral sub-
stance in the human vertebral
column.

220. No Sternum or Pcl-
Tis. — The Sternum and Pel-
vis are both wanting in fishes,
and the anterior and posterior
extremities are rudimentary,
being represented by fins.

Fig. 112.

Skeleton of the Perch.

Fig. 113.

Section of the bony scale of Lepidostens. a. Showinsr tlic regular distribution of tho
Lacunae and of the connectino; Canaliciili. I. Small portion more liighly magnified.

219. What are the only Yertebrrc of Fishes ? What is peculiar about their .irticula-
ting surfaces ? 220. Why have Fishes no Sternum or Pelvis ?

102

HITCHCOCK'S ANATOMY

221. Head, — The bones of the Head in this class of ani-
mals are numerous and exceedingly complicated, being in
fact a difl&cult portion of study in comparative osteology. It
is, however, a subject of great interest to a thorough scholar
of this branch of anatomy ; but as so little of it can be gen-
eralized, it must be omitted h,re altogether.

222. Great Vdriety of Teeth.— The Teeth present every
possible variety in position and size, and, as Sir Richard
Owen says, "they average in number from zero to count-

Fia. 114.

JiVf

Ilead of the Pike. c. Cranium, n. Nasal Fossjb. im. Intermaxil'aiy Bone.
m. Upper Jaw. p., op., io. Bones peculiar to the head of fishes.

less quantities." Some teeth, in shape and lob&cion re-
semble the pavement of the street, others are of a delicate
hook-shape, and others still are fine as hairs, and are located

Fig. 115.

Head of a Shark.

221. What is remarkable with respect to the bones of the Head in this class? 222. Whaf
Is said about the variety of Tishes' Teeth ? How numerous are they found at times?

AND PHYSIOLOGY

103

on the jaws, tongue, and palate. They are repeatedly re-
newed during the life of the animal. Fig. 116 represents
the microscopio structure of the tooth of an Eagle E,ay.

Fig. 116.

Microscopic struefeure of Tooth of Eagle Eay.

223. Skeleton, or Harder Parts of Invertebrata— The
harder parts of invertebrate animals generally differ so much
from bones in composition and structure that the term Osteo-
logy may perhaps be less proper than that of Skeleton in
describing them.

224. Skeletons of Crustaceans.— Among the Articu-
lata the Crustaceans have a more or less solid external crust
of carbonate of lime in a base of peculiar azotic matter, in-
soluble in caustic potash, called Chitine.

225. Skeletons of Insects . — Insects, the most numerous
class of articulated animals, have a chitinous covering, gener-
ally leathery, but sometimes solid. The Arachnoidea have a
similar skin, soft or coriaceous, rarely horny ; and the Anne-
lida a very thin epidermis. The Helminthes, Rotatoria, and
Turbellaria, reckoned in this branch of the animal kingdom

What is curious about their renewal?
225. What is the skeletoa of Insects?

224. Describe the skeletou of Crustaceans?.

6*

104 HITCHCOCK'S ANATOMY.

by some eminent writers, have a skin more or less hard, and
sometimes spinous.

Fig. IIT.

Microscopic structure of tlac Spine of Sea Hedge-Hog.

226. Skeleton of the Mollusca. — In all the three
great classes of Molluscs, the Acephala, the Cephalophora,
and the Cephalopoda, the animal possesses a mantle bj which
it is able to secrete a solid deposit, mainly composed of car-
bonate of lime, which it spreads over nearly all the body, and
is fastened to it by muscles. In the Acephala this skele-
ton is in two pieces, called valves ; in the Cephalophora, it is
in one piece, except that a calcareous plate is attached to the
foot to close the orifice. The organic base of these shells
sometimes, but rarely, predominates over the calcareous part.
In the Cephalopoda there are cartilages for the attachment of
muscles similar to the same substance in vertebrate animals.
In the Argonauta and Nautilina of this class, the mantle
secretes an external shell ; but in the Loligina, or Cuttle Fish
family, it is internal.

The structure of the shells of Molluscs is often complicated
and beautiful.

227. Skeletons of the Racliata. — Among the Polypi
some are entirely soft ; others have a solid skeleton, which

22G. Describe the skeleton of Molluscs. 227. What are the skeletons of Radiates?
What is their chemical oorapositioa ? , . .

AND PHYSIOLOGY,

Fig. 118.

105

Microscopic view of Shell of Pinna.

is calcareous, hornj, or leathery. This skeleton, called a
poljparj, or in popular language coral, is secreted by the
skin of the animal, and seems to be truly an internal skele-
ton. It contains, say ninety-five per cent, of carbonate of
lime, some two or three per cent, of fluorides and phosphates,
and from four to eight per cent, of organic matter.

The Acalephae, another class of Radiates, are mostly gela-
tinous ; but a few are cartilaginous, and some have a nuclear
skeleton. The Echinodermata, with few exceptions, have an

Fig. 119.

Microscopic section of hinge of Mya showing a crystalline Btructur©.

What is ooral ? What is the skeleton of other Radiates f

106 HITCHCOCK'S ANATOMY.

external skeleton highly calcareous. In the Asteroidea there
is also an internal articulated skeleton. The structure of
these skeletons is too complicated for description here. The
Echinidae arc remarkable for calcareous knobs and rays, both
sharp and blunt, sometimes several inches long ; hence this
common name, Sea Hedge-Hog, or Porcupine.

Skeletons of the Protozoa. — The organisms brought
together by Prof. Owen under Protozoa, are the Amorphozoa
or Sponges, the Foraminifera, and Infusoria, "which," he
says, "manifest the common organic characters, but without
the distinctive super-additions of true plants or animals." Of
the skeletons of the Infusoria we know little, save that they
occur fossil, and are composed of silica and iron ore.

The Foraminifera are small, gelatinous animals, protected
by a calcareous shell. The Sponges are said to be ceratose
or horny ^ siliceous or flinty ^ and calcareous or liTny, accord-
ing as their frame- work partakes of these several characters.

What is said of the skeletons of the Protozoa? What of the Forminifera?

CHAPTER SECOND.

THE MOVING POWERS OF THE SYSTEM.— MYOLOGY, OR THE
HISTORY OF THE MUSCLES.

DEFINITIONS AND DESCRIPTIONS.

228. Microscopic Structnrc of Muscle. — The Muscles,
known as flesh or lean meat, compose a large part of the
extremities, and the covering of the trunk. To the naked
eye they appear to be fibrous, and, with the assistance of the
microscope, these fibers are found to be bundles — called Fasci-
culi— of still smaller fibers, called Ultimate Fibers. These
seem to be polygonal in form, and with an average diameter
of 4^uth of an inch in man, though in some of the lower ani-
mals their size is much less.

View of the stages of development of ' FiG. 120,

Muscular Fiber. 1, A Muscular Fiber of
Animal life enclosed in its Sheath or
Myolemma. 2, An Ultimate Fibril of tho
Bame. 3, A more highly magnified View
of Fig. 1, showing the trne nature of the
Longitudinal Strise, as well as the mode of
formation of the Transverse Stria?. The
Myoleinma is here so thin as to permit the
Ultimate Fibrils to be seen through it. 4,
A Muscular Fibre of Organic life with two
of its Nuclei ; taken from the Urinary Blad-
der, and magnified GOO Diameters. 5, A
Muscular Fibre of Organic life from the
Stomach, magnified the sam.e.

229. Fibrils. — The ulti-
mate fibers are still further divisible into what are termed
Fibrils. These have an average diameter of about ToiFuth

228. What is lean meat ? How docs muscle appear to tho naked eye ? What are tho
three microscopic elements? Describe each. 229. What is tho diameter of the Fibrils^;

108

HITCHCOCK'S AX ATOMY

Fig. 121.

A View of the Fragments of Stri[)ed clcmontary Fibers, showing a cleavage in opposite
directions — magnifie<l 300 Diameters. 1, The Longitudinal Cleavage. 2, The Transverse
Cleavage, the Longitudinal Lines being scarcely visible. 3, Incomplete Fracture, follow-
ing the opposite surfaces of a Disc which stretches across the Interval and retains the two
Fragments in connexion. The Edge and Surface of this Disc are seen to be minutely-
granular, the Granules corresponding in size to the thickness of tlie Disc and to the dis-
tance between the faint Longitudinal Lines. 4, Another Disc nearly detached. 5, A de-
tached Disc more highly magnified, showing the Sarcous Elements. G, Fibrilhc separated
by violence from each other at the broken end of the Fiber. 7,8, The two appearances
commonly presented by the separated single Fibrillse ; more highly magnified, at 7 the
spaces are rectangular, at 8 the borders are scalloped and the spaces bead-like.

of an inch, and number about 650 in each ultimate fiber.
They are unprotected by any covering, while both the fasicu-

FiG. 122.

kis and ultimate fiber
are everywhere pro-
tected by a delicate
sheath called the
Sarcolemma.

230. Organic, or
Unslripcd, and Ani-
mal, or Striped Fi-

Fibrils of Human Muscle. bCTS. All the mus-

cles of the body are divided into two classes, according to
their function. Those necessary for carrying on the vital
functions, such as breathing and digestion, are called Or-
ganic, and those under the control of the will Animal Fi-
bers. In addition to their use as a means of distinction,
they may be known by their appearance under the micro-

What is the Sarcolemma? On what clement of muscle is this Vauting? 230. Givo
the two functional classes of tho muscles.

AND PHYSIOLOGY.

109

Fig. 123.

Fig. 124.

A broken Muscular Fiber sho^ving tho
sheath or myolemma untorn.

Fig. 125.

Transverse Section of Iluinan FibrillaB
showing a Polygonal Ibrm.

scope, the Animal !Fiber being
marked bj transverse striss,
or stripes resembling a beaded
filament, called Striped Fi-
ber; and the Organic being
made up merely of flattened
bands destitute of these cross
marks, and hence called Un-
striped, or smooth fiber. The
unstriped fibrils are developed
from cylindrical or spindle-
shaped nucleated cells, and
are surrounded by a peculiar
fluid known as muscle juice,
which is unlike the plasma of
the blood, since it contains
casein.

231. Tendons, Aponeuro-
ses, Belly or Swell of the Mus-
cle.— The extremities of the
muscles are composed of dense
areolar tissue in the form of
tendons or cords, and that
extremity which is nearest to
the center of motion is called the Origin, while the one most

Fusiform Cells of Smooth Muscular Fi-
ber, a. Two cells in their natural state.
l>, A cell treated to acetic acid, showing tho
nucleus c.

What is the appearance of tho Animal Fibre under tho microscope? Also that of tli©
Organic ? 231. Stat© the composition of the. Tendons.

110

HITCUCOCK'S ANATOMY

remote from it is called its Insertion. These are exceedingly
firm and strong, perfectly inelastic, and can not be torn from
the bones without unnatural violence. If the extremity of
the muscle has a large surface for attachment, its tendon is
expanded into a broad membranous portion termed an Apo-
neurosis, as may be seen in the muscles inclosing the abdo-
men ; while the greater portion of the muscles have a fleshy
portion called the Swell or Belly, and the tendinous portion
contracted into the shape of a cord, or even of a thread. In
general this belly of the muscle is in a place which is the
most firmly fixed, and distant from the point to be moved, in
order to effect grace of motion, and beauty of form.

Fig. 126.

A Eadiate Muscle.

282. Forms of Muscles. — In form the muscles present a
great diversity. A Radiate Muscle (Fig. 126) is one where
the fibres radiate from a central portion to distribute them-
selves upon a large surface. In the Fusiform (Fig. 127) the

Fia. 121.

A Fusiform Muscle.

fibres diminish in size from a center to each extremity. In

What ii the fleshy portion of the masclc called ? What is an Aponeurosis ? Define the
Origin and Insertion of a innscle. Where is the Belly of the muscle generally located ?
232. Dosciibo the Radiate aad Fusiform Muscles.

AND PHYSIOLOGY. Ill

Fig. 128.

A Doubly Penniform Muscle. ^

the Penniform the fibres are short and arranged npon a long
tendinous line, like the plumes upon the quill of a feather.
The circular form, called Sphincter, is found in parts of the
b )dj where the fibres are circular, surrounding some orifice
which they partially or entirely close up by their contraction'.
An example of this is seen around the eye and mouth. A
few muscles resemble in structure a ribbon. Others a cord,
and others are very thin and expanded, so that they resemble
a membrane. All these forms are thus arranged to secure
the greatest amount of power with dispatch, and also the most
perfect freedom of motion, as Avell as to adapt themselves to
the amount of space furnished them on the skeleton.

233. Number of Muscles, Single Muscles.— The number
of muscles in man is 540, being more than twice the number
of the bones. They are nearly all arranged in pairs ; that is,
both sides of the body have similar muscles, while the single
or unmated muscles are only thirteen. Each muscle is pro-
vided with one or more antagonist muscles, or those which
produce motion in an opposite direction, save a very few sur-
face muscles about the head and neck, where the elasticity of
the integuments produces the antagonistic motion.

234. Fascia. — Every muscle is covered by a firm and
slightly elastic membrane called Fascia, which serves the
double purpose of keeping the fibres firmly in their place, and
also of producing a tonic pressure, which gives increased
strength to the muscle. An illustration of the utility of this
pressure is seen in the fact, that the school-boy, when engaged
in running as rapidly as possible in his sports, ties a handker-

Describe the Penp.iform and Circular Muscles. Are there ^iny other forms of muscles?
Why are muscles of these different shapes ? 2-33. What is the number of human muscles?
How docs this compare with the number of the bones? IIow many unmated muscles
arc there? What is meant by antagonist muscles ? 234. What is the Fascia, and what
purpose does it serve ? What illustration of its use ?

112

HIT^CHCOCK'S ANATOMY

Pig. 129.

Anterior View of the Muscles of the Body.

1, Frontal Bellies of the Occipito-Frontalis.

2, Orbicularis Palpebrarum. 3, Levator Labii
Superioris Aliieque ISJasi. 4, Zygomaticus Mi-
nor. 5, Zygoinaticus Major. 6, Masseter. 7,
Orbicularis Oris. 8, Depres&or Labii Inferions.
9, riatysma-Myoides. 10, Deltoid. 11, Pccto-
ralis Major. 12, AxMUary poition of the Latis-
einius Dorsi. 13, SurraL is
Major Anticus. 14, Bicepa
Flexor Cnblti. 15, Anterior
Portion of the Triceps Ex-
tensor Cubili. 16, Supinator
Kadii Longus. 17, Pronator
Kadii Teres. 18, Extensor

Carpi Eadialis Longior. 19,
Extensor Ossis Metacarpi
PoUicis. 20, Annular Liga-
ineut. 21, Paluuir Fascia.
22, Obliquus Externus Ab-
dominis. 23, Linea Alba. 24,
Tensor Vaginae Femoris. 25,
Section of the Spermatic
Cord. 26, Psoas Magnus*
27, Adductor Longue. 23,
Sartorius. 29, Eectus Fe-
moris. 30, Vastus Exter-
nus. 31, Vastus Internus.
82, Tendon Patellae. 33, Gas-
trocnemius. 34, Tibialis An-
ticus. 35, Tibia. 36, Ten-
dons of the Extensor Com-
manis.

AND PHYSIOLOGY

113

Fig. 130.

Posterior "View of the Muscles of the
Body. 1, Temporalis. 2, Occipital por-
tion of the Occipito-Frontalis. 3, Corn-
plexus. 4, Splenius. 5, Masscter. 6,
Sterno-Cleido Mastoideus. 7, Trapezius.
8, Deltoid. 9, Infra-Spinatus. 10, Tri-
ceps Extensor. 11, Teres Minor. 12, Te-
res Major. 18, Tendinous portion of tho
Triceps. 14, Anterior Edge
of the Triceps. 15, Supinator
Eadii Longus. 16, Pronator
IJadii Teres. 17, Extensor
Communis Digitorum. 18, Ex-
tensor Ossis Metacarpi Polli-

cis. 19, Extensor Communis Di-
gitorum Tendons. 20, Olecranon
and -Insertion of the Triceps. 21,
Extensor Carpi Ulnaris. 22, Au»
ricularis. 23, Extensor Commu-
nis. 24, Latissimus Dorsi. 25, Its
Tendinous Origin. 26, Posterior
Part of the Obliquus Externus.
, Gluteus Medius. 2S, Gluteus
Magnus. 29, Biceps Flexor Cru-
ris. 30, Semi-Tendinosus. 31,
32, Gastrocnemius. 33, Tendo-
Achilles.

114

HITCHCOCK'S ANATOMY

'^^^- ^^1- chief about his Tvaist in order

to give strength to his mus-
cles. And so important is
this membrane to the muscu-
lar system, that, upon the
thigh, where very great
strength and rapidity of
movement is required, this
membrane is thicker than in
most of the other parts of the
body ; and not only so, but a
muscle is also provided for the
especial purpose of rendering
this membrane very tense,
when any violent action is
required, or its own elasticity
is insufficient.

235. Descriptions of par-
ticular Muscles. — In such a
treatise as the present one, it
will of course be impossible
to describe all the muscles as
minutely as the bones have
been, nor will it be necessary ;
but only those which are the
most interesting and instruc-
tive.

236. Orbicularis Palpebra. — The muscle which surrounds
the eye is a sphincter which is made of circular fibres, and
when contracted closes the eye, as it is termed. Consequently
this action requires the movement of no bones, and no attach-
ment to any thing but the soft pa,rts of the face. It is called
the Orbicularis Palpebr^.

A Transverse Section of the Neck, show-
ing the Fascia Profunda, and its Pro-
longations as Sheaths for the Muscles.
1, Platysma Myoides. 2, Trapezius. 3,
Ligamentum NuchiB. 4, Sheath of Sterno-
Cleido-Mastoid. 5, Muscle itself. C, Point
of Union of its Fascia. 7, Point of Union
of the Fascia Profunda Colli of each side
of the Neck. 8, Section of the Sterno-
Ilyoid Muscle. 9, Section of the Omo-
Ilyoid Muscle. 10, Section of the Sterno-
Thyroid Muscle. 11, Lateral Lobe of the
Thyroid Gland. 12. Trachea. 13, (Esoph-
agus. 14, Blood-vessels and Pneumogas-
tric Nerve in their Sheath. 15, Longus
Colli. 16, Eectus Anticus Major. 17,
Scalenus Anticus. IS, Scalenus Medius
and Posticus. 19, Splenius Capitis. 20,
Splenius Colli. 21, Levator Scapula. 22,
Complexus. 23, Trachelo - Mastoid. 24,
Transversalis Cervicis. 25, Cervicalis Dc-
scendens. 26, Semi-spinalis Cervicis. 27,
Multifidus SpinsB. 2S, A Cervical Vertebra.

Its antagonist is the Levator Pal-

What is said about the importance of tliis fascia upon the thigh ? 236. Wliatis the mus-
cle tliat opens and closes the eye, as it is termed? What kind of a muscle Is this?
What is the antagonist of the Orbicularis Palpebraa ?

axd physiology
Fig. 132.

115

A Front View of the Superficial Layer of Muscles on the Face and Neck. 1, 1, Ante-
rior Bpllies of the Occipito-Frontalis. 2, Orbicularis or Sphincter Palpebrarum. 8, Na«
sal Slip of Occipito-Frontalis. 4 Anterior Auriculae. 5, Compressor Naris. 6, Levator
Labii Superioris Ahequo Nasi. 7, Levator Anguli Oris.- S, Zygomaticus Minor. 9,
Zygomaticus Major. 10, Masseter. 11, Depressor Labii Superioris Alseqne Nasi. 12,
Buccinator. 13, Orbicularis Oris. 14, The denuded Surface of the Inferior Maxillary
Bone. 15, Depressor Anguli Oris. 16, Depressor Labii Inferioris. 17, The portion of
the Platysma Myoides that passes on to the Mouth, or the Musculus Kisorius. IS, Stcrno-
Ilyoideus. 19, Platysnia-Myoides. It is wanting on the other side of the Figure. 20,
Superior Belly of the Omo-Hyoideus near its insertion. 21, Sterno-Cleido-Mastoideus.
22, Scalenus Mcdius. 23, Inferior Belly of Omo-Hyoid. 24, Cervical Edge of the Tra-
pezius.

pebrse, which takes its origin far back on the sides of the
cavity of the orbit, and is attached to the upper lid. When
contracted it opens the eye.

237. Orbicularis Oris. —The Orbicularis Oris (circular
muscle of the face) by its contraction closes the mouth. Like
the corresponding muscle of the eye, it has its origin and in-
sertion in the soft parts of the face, and u made up of concen-

257. "Where is the Orbicularis Oris, and what is its use?

116 TI IT ClI C O C K'3 anatomy

trie fibres. And tlic antagonists are those muscles -which are
inserted into it, coming from the diifferent bones of the face
moving the lips and nostrils, and giving much of the expres-
sion of emotion in the countenance.

238. Masseter and Temporal Muscles.— The elevators of
the lower jaw are two : the Masseter (chewing) and the
Temporal (from the bone on which it lies). They are at-
tached to the posterior portion of the bone near the joint, since
if their position was nearer to the front part of the bone they
would not contract sufficiently to bring the jaws together.

239. Digastric Muscle. — The lower jaw is carried down-
wards by the Digastricus (tvro bellies) muscle. This is a long
round muscle like a cord, which commences just below the
lower front teeth, and from thence runs downwards and back-
wards to the 03 hyoides, where it runs through a tendinous
loop ; after this it passes upwards and backwards to the mas-
toid process upon the temporal bone, just behind the ear.
The contraction of this muscle then will open the mouth, when
the OS hyoides is made fast ; but if the jaw be confined by
its elevator muscles, the os hyoides will be the movable por-
tion, and will be elevated. The necessity of such an arrange-
ment is evident from the fact, that no muscle from the jaw to
the hyoides would be of sufficient length to open the lower
jaw by its contraction ; and if it were to run backwards to
the spinal column, the violence with which it must contract
to accomplish its object, would produce such pressure upon the
vessels and nerves of the neck as to injure them.

240. Stcrno-Clcido-Iflastoidcus. — A bow, or bending of
the head upon the spinal column, is effected by the action of
the Sterno-Cleido-Mastoideus muscle (named from its attach-

Wliat arc its antagonists? What muscles aid verj much in giving expression to tha
countenance ? 20S. What arc tlic two pairs of muscles that bring tlic jaws together in
the act of chewing? 230. State the muscle that opens tlic mouth. What mechanical
peculiarities in its structure and operation? Why tlic necessity of such a complicated
arrangement ? 240. Whut is the musclo by whose action we bow the head ?

AND PHYSIOLOGY.

Fig. 133.

117

A Lateral View of tlie Deep-seated Layer of Muscles on the Face and Neck. 1, Tem-
poral Mnscle deprived of its Fascia. 2, Corrugator Supercilii. 3, Nasal Slip of the Ocr
cipito Frontalis. 4, Superior or Nasal Extremity of the Levator Labii Superioris Alaequo
Nasi.. 5, Compressor Naris. C, Levator Anguli Oris. 7, Depressor Labii Superioris
ALTquc Nasi. S, Buccinator. 9, Orbicularis Oris. 10, Depressor Labii Inferioris. 11,
Levator Labii Inferioris. 12, Anterior Belly of the Disastricus. 13, Mylo-Hyoid. 14,
Sty'o-IIyoid. 15, Thyro-TIyoid. 16, Upper Belly of the Omo-IIyoid. 17, Stcrno-Cleido.
Mastoid. IS, Sterno-IIyoid. 19. Scalenus Anticus. 20, Pectoraiis Major. 21, Deltoid.
22, Trapezius. 23, Scalenus Jiledius. 24, Levator Scapula3 and Scalenus Posticus. 25.
Splenius. 2G, Complexus.

ment to the Sternum, Clavicle, the Greek for which is kleis,
and the mastoid process). The form of this muscle is essen-
tially that of a thick ribbon.

241. Muscles of the Scapula.— The Scapula is covered
with muscles on both sides, most of which are inserted into
the head of the humerus. Their use is to rotate the hu-

What is tho shape of this muscle ?
offset?

!il. What actions do tho muscles of the scapuli

118

HITCHCOCK'S A N A T O ^[ Y

Fig. 134.

A Yicw of the Muscles of tlio Back as shown after the reraoval of the Integuments, 1
Occipital Origin of tlic Trapezius. 2, Stcrno-CIeido-Mastoideus. 8, Middle of the Tra.
pozius. 4, Insertion of the Trapezius into the Spine of the Scapula. 5, Deltoid. 6, Sec-
ond Head of the Triceps Extensor Cubiti. 7, Its Superior Portion. 8, Scapular portion
of the Latissimus Dorsi. 9, Axillary Border of tJie Pectoralis Major. 10, Axillary Bor-
der of the Poctoralis Minor. 11, Scrratus Major Anticus. 12, Infra-Spinatus. 13, Teres
Minor. 14, Teres Mnjor. 15, Middle of the Latissimus Dorsi. 16, External Oblique of
the Abdomen. 1", Gluteus Medius. 18, Gluteus Minimus. 19, Gluteus Magnus. 20,
Fascia Lumborum.

merus, as well as to give it protection where it articulates
with the scapula, and to keep it in ita place.

AXD PHYSIOLOGY

119

242. Biceps.— The Biceps
(two heads, or points of at-
tachment) is the muscle which
flexes or bends the arm to-
wards the bodj. It arises
from the head of the humerus
and scapula, and is inserted
into the upper end of the
radius. It is a ver j fine ex-
ample of a fusiform muscle,
and though acting at a great
mechanical disadvantage as to
power, it effects a rapid move-
ment.

243. Triceps.— The Tri-
ceps (three heads), its antag-
onist, is similar in its general
form, and is attached to the
ulna instead of the radius.
It is situated upon the poste-
rior side of the humerus, and
the force with which it may
be made to contract, is seen
in the powerful blow given
by the boxer, or the weights
raised bj extending the arms
upon the instrument made for
the purpose in a gymnasium.

244. Muscles of the Forc-
A r m . — The Fore- Arm is abun-

A View of tlie Muscles on the Front of
tlie Arm, 1, Clavicle. 2, Coracoid Pro
cess and Origin of the Short Head of the
Biceps. 3, Acromion Scapula. 4, Head
of the Os Humeri. 5, Tendon of the Bi-
ceps Muscle in the Bicipital Groove. 6,
Ligamentum Adscititium dissected oflf. 7,
Cut portion of the Pectoralis Major. 8,
Long Head of the Biceps. 9, Insertion ol'
the Deltoid. 10, Cut portion of the Ten-
dinous Insertion of the Pectoralis Minor. 11, Coraco-Brachialis. 12, Short Head of
the Biceps. 13, Latissimus Dorsi. 14, Inner portion of the Triceps. 15, Body of tho
Biceps. 16, Outer portion of the Triceps. 17, Brachialis Internus. IS, Origin of tho
Flexor Muscles. 19, Brachialis Internus near its Insertion. 20, Tendon of the Biceps.
21, Fasciculus from the Biceps Tendon to the Fascia Brachialis. 22, Flexor Carpi Ea-
dialis. 23, Palmaris Longus. 24, Supinator Radii Longus.

242, Why is the name Biceps given to the muscle that fljxes the fore-arm ? What
mechanical disadvantage in its structure? What gain from it? 213. What Is the antag-
onist of the Biceps? What actions show its mode of action ?

6

120

HITCHCOCK'S ANATOMY

I'iG. 136. dantlj supplied with muscles,

many of which are fusiform
in their appearance, and all
of w^hich are for the purpose
of moving the hand and fin-
gers. Most of the fibres run
in a direction parallel to the
bones of the fore-arm, but
those which perform the ac-
tions of pronation and supina-
tion lie obliquely, and some
nearly at right angles to the
long muscles. In this part
of the body the muscles are
distinguished by slenderness
of form and consequent deli-
cateness of tendon, the latter
in many cases being equal in
length to the muscular fibre,
since there are very few mus-
cles below the wrist, and those
only which are short and
thick, for the purpose of mov-
ing the thumb and little
finger.

245. Tendons of the Fin-
gers.— The arrangement of
the tendons which are at-
tached to the phalanges, for
the motion of the fingers,
shows the contrivance and
skill of an Infinite Being. In
order that the fingers may bo slender and easily moved, it is
desirable that there should be as small a quantity of matter in

A View of the Outer Layer of the Mus-
cles on the Front of the Fore-Arm (Flex-
ors). 1, LoAver portion of the Biceps
Flexor Cubiti. 2, Brachialis Internus. 3,
Lower Internal portion of the Triceps. 4,
Pronator Kadii Teres. 5, Flexor Carpi
Eadialis. G, Palinaris Longns. 7, Part of
the Flexor Subllmis Digitorum. 8, Flexor
Carpi Ulnaris. ~ 9, Palmar Fascia. 10,
Pahnaris Brevis Muscle. 11, Abtluctor
Pollicis Manus. 12, Portion of the Flexor
Brevis Pollicis Manus. The Line crosses
the Adductor Pollicis. 13, Supiiiator
Longus. 14, Extensor Ossis Metacarpi
Pollicis.

244. Give the general :i:-r:in^;omeIit of muscles in the fyre-afm.
and Supinators He?

How do the Pronators

AND PHYSIOLOGY. 121

Fia. 137. Fig. 138.

A View of the tnuscles on the Palm of

the Hand. 1, Annular Ligament. 2, 2,

Origin and Insertion of the Abductor Pol-

licis. 3, Opponens Pollicis. 4, 5, Two

Bellies of the Flexor Brevis Pollicis. 6,

Adductor Pollicis. 7, T, Lunibricales aris-
ing from Tendons of the Flexor Profundus

Digitornm. S, Shows how the Tendon of

the Flexor Profundus passes through tho

Flexor Sublimis. 9, Tendon of the Flexor

Longus Pollicis. 10, Abductor Minimi

Digiti, 11, Flexor Parvus Minimi Digiti.

12, Pisiform Bone. 13, First Dorsal Inter- ^ y.^^ ^^ ^^^ ^^^^^ j^^^^^ ^^ j^^^^^^,

osseous Muscle. on the Front of the Fore-Arm (Flexors).

1, Internal Lateral Ligament of the El-
bow-Joint. 2, Capsular Ligament of the Elbow-Joint. 3, Coronary Ligament of tho
Head of the Radius. 4, Flexor Profundus Digitorum Perforans. 5, Flexor Longus
Pollicis. G, Pronator Quadratus. 7, Adductor Pollicis Manus. 8, Lumbricales. 9,
Interossei.

tliem as possible. Hence, as above stated, the muscle that
moves them is situated in the fore-arm, and the tendon is
made as slender as possible. But here another arrangement
claims our attention. A set of four tendons from a common
muscle is attached to the base of the second phalanx of each
finger, and a second set to the third row of phalanges. The
question then arises, how can these two tendons pass upon

245. l>esaril>e tho arrans^emcnt of the tendons of tho flugers.

122 HITCHCOCK'S a x a t o :si y

both sides (upper and lower) of the finger and be firmly
enough secured to the finger to keep them in place, without
making the finger of an unwieldy bulk, and at the same time
allow the force to be applied upon the center of the finger
rather than upon one side ? The answer is this : the muscle
which sends its tendons to the second phalanx lies above the
other set of tendons, and where the superior tendons join the
second phalanx, they are each split into two parts, through
which the tendons of the lower muscle pass to the last pha-
lanx, and move freely without interruption from the superior
muscle or tendons. This arrangement is found in the foot,
as well as in the hand, for giving the same motion to the
t033, and very much resembles the movement of a cord
through a loop.

246. Muscles of the Tiiumb and Little Finger.— The
thumb and little finger, as already mentioned, are supplied
with separate muscles in the body of the hand, mainly for the
purpose of giving motion from side to side, as well as a partial
rotation. In addition to this, there are several muscles upon
the fore-arm which give their tendons only to these two ex-
tremities. The obvious use of this arrangement is to give
strength and great variety of motion so necessary in the
thumb and little finger.

247. Muscles of the Back, Dorsal Muscle. — Upon the
back are found at least thirty pairs of muscles, which are ar-
ranged in six layers. These are of various forms and sizes,
with complicated and obscure attachments. The main use of
these muscles, taken as a group, is to keep the trunk in an
upright position, and give a firm attachment for muscles to
move the extremities. The outermost layer is very super-
ficial, lying directly under the skin, while the deepest layer
is deeply imbedded between diiferent processes of the vertebrae.

Why must one tendon pass through nnother rather than pass along by its side?
1)0 WG find this arrangement upon both hands and feet? 246. Which two extremities
of the hand have the moit muscles given to them? 24". How many pairs of muscles
iipon the back of the body? Give the number of layers into which they may bo dis-
sected. State tlie essential purpose of theai.

AND PHYSIOLOGY.

Fig. 139.

123

A View of the Second Layer of Muscles of the Back. 1, Trapezius. 2, A portion of
the Tendonous ellipse formed by the Trapezius on both sides. 3, Spine of the Scapula.
4, Latissimus Dorsi. 5, Deltoid. 6, Infra-Spinatus and Teres Minor. 7, External Ob-
lique of the Abdomen. S, Gluteus Medius. 9, Gluteus Magnus of each side. 10, Leva-
tor Scapulffi. 11, Ehomboideus Minor. 12, Ehomboideus Major. 13, Splenius Capitis.
14, Splenius Colli. 15, A portion of the Origin of the Latissimus Dorsi. 16, Serratus In-
ferior Posticus. 17, Supra-Spinatus. IS, Infra-Spinatus. 19, Teres Minor. 20, Teroa
Major. 21, Long Head of the Triceps Extensor Cubiti. 22, Serratus Major Anticus. 23;
Internal Oblique of the Abdomen.

The largest muscle of the back (hence the name Dorsal) i;
of value to move the arm 5. It has its origin from the lum-
bar and sacral vertebrae, and the posterior third of the crest
of the ilium, and is inserted bj a short tendon into the upper
extremity of the humerus. The action of this muscle brings

Give the origin and insertion of the Dorsal muscle. State its action.

124 HITCHCOCK'S ANATOMY

the arm downwards and backwards, as in the movements of
chopping wood or striking with the blacksmith's sledge. But
when the hands are made the fixed points, the bodj is raised
upwards.

248. Superior and Inferior Serrall. — Two muscles of the
back are used in forced or violent respiration. These are the
Superior and Inferior Serrati Muscles. The Superior Ser-
ratus arises from the three lower cervical and two upper dorsal
vertebrae, and runs downwards and forwards to be inserted
into the border of the second, third, and fourth ribs. The
Inferior Serratus arises from the last two dorsal and three
upper lumbar vertebrae, and, running upwards and forwards,
is inserted upon the four lower ribs. The name of these mus-
cles means in Latin " saw-like," since the portions w^hich join
upon the ribs resemble the teeth of a saw. The former of
these elevates the ribs, thereby enlarging the cavity of the
chest, while the latter assists in its compression by depressing
the ribs, and consequently the diaphragm, downwards.

249. Tlic Diaphragm.— But the essential muscle of respi-
ration is the Diaphragm. This, as its name implies, is a par-
tition across the body just below the lungs, — with three
large openings, — which separates the thorax from the abdo-
men. Its attachments in general terms may be said to be
upon an oblique line drawn about the body just below the
ribs, which line intersects the first lumbar vertebra, where
the central tendon of the Diaphragm, as it is termed, is at-
tached. When relaxed, it presents the appearance of an in-
verted and irregularly shaped cup or basin, but when in a
state of contraction it becomes nearly a plane surface. Hence
this muscle enlarges the chest by depressing its lower surface,
thereby forming a partial vacuum.

24S. Which muscles of the back arc f-scd in forced respiration? Give the origin and
insertion of llie two Serrate Muscles. Wliy called "Serrate?" 249. Give tlie form of
tl'.c Diaphragm. Wliat two cavities of the body docs it separate? What is it an essen-
tial agent in effecting ?

and physiology.

Fig. 140.

125

ATie-w of the Under Side of the Diaphragm. 1, 2, ?., The Greater Miisclo of the Dia-
phragm inserted into the Cordiform Tendon. 4, The small triangular space behind the
Sternum, covered only by Serous Membrane, and through ■which Hernia sometimes
pass. 5, Ligamcntum Arcuatum of the Left Side. G. Point of Origin of the Psoas Mag-
nus. 7, A small Opening for the Lesser Splanchnic Nerve. S, One of the Crura of the
Diaphragm. 9, Fourth Lumbar Vertebra. 10, Another Crus or portion of the Lesser
Muscle of the Diaphragm. 11, Hiatus Aorticus. 12, Foramen CEsophagcum. 13, Fora-
men Quadratuin. 14, Psoas Magnus Muscle. 15, Quadratus Lumborum.

250. Intercostal Muscles. —Between the ribs arc placed
two sets of muscular fibres, an external and an internal, called
the Intercostal Muscles, which hj their action draw the ribs
upwards. The fibres run in a diagonal direction from one rib
to another, so that the greatest length may be given for their
contraction without compromising too much of their power.
And hence we can sec that w^hile the first rib is firm and im-
movable, by contraction of these fibres the ribs must bo raised,
and by their relaxation they must be depressed. The exter-
nal fibres run downwards and towards the middle line of the
abdomen, while the internal run downwards and backwards.

251. Abdominal Muscles.— The principal muscles of the
abdomen are large and thin expansions of muscular fibres,

250. Give the arrangement of fibres in the Intercostal Muscles. 251. What forms tlio
principal part of the Avails of the abdomen ?

126

HITCHCOCK'S ANATOMY

Tig. 141. which completely cover tho

space below the border of tho
ribs, and above the innomiiiu-
tum. They are arranged un-
der four different names, since
they run in different direc-
tions as they encircle the ab-
domen. By their contraction
they press upon the digestive
organs, and thus diminish the
cavity of the abdomen, and,
in proportion to the elasticity
of the diaphragm, the thorax
also. Hence these are the
essential instruments in cough-
ing, laughing, crying, and
sneezing, as well as in sing-
ing, shouting, or any action
requiring expulsive effort. By
their elasticity they also per-
form the function of expira-
tion in natural breathing, as
well as keep up a tonic pres-
sure upon the stomach and
alimentary canal.

252. Great Psoas Muscle.
— The Great Psoas Muscle,
known in animals as the ten-
der loin (from the Greek
signifying a loin), is the
one which bends the thigh upon, or towards the trunk.
It has its origin from the last dorsal and four upper lum-
bar vertebrae, and passes from thence downwards and for-
wards, gliding over the edge of the innominatum, and attaches

Under how many Leads are they arranged? What actions do thoy accomplish when
contracted ? 252. What is the scientific name of tho " tender loin ?"' Give its attach-
ments.

A Lateral View of the Muscles of the
Trunk, especially on the Abdomen. 1,
Latissimus Dorsi. 2, Serratus Major An-
ticus. 3, Upper portion of the External
Oblique. 4, Two of the External Inter-
costal Muscles. 5, Two of the Internal
Intercostal Muscles. G, Transversalis Ab-
dominis. 7, Fascia Lumborum. 8, Poste-
rior part of the Sheath of the Eectu?, or
Anterior Aponeurosis of the Transversalis
Muscle. 9, The Eectus Abdominis cut off
.lud in its Sheath. 10, Eectus Abdominis
of the Ei-ht Side. 11, Crural Arch. 12,
Gluteus Magnus — Medius and Tensor Va-
giniE Femoris covered by the Fascia Lata.

AND PHYSIOLOGY.

Fig. 142.

127

A View of the Superficial Muscles of the Left Side, and of the Deep Muscles of- the
Eight Side, on the Front of the Trunk. 1, Pectoralis Major. 2, Deltoid. 3, Anterior
Edge of Latissimus-Dorsi. 4, Serrated Edge of Serratus Major Anticus. 5, Subclavius
Muscle. 6, Pectoralis Minor. 7, Coraco-Brachialis. 8, Biceps Flexor Cubiti. 9, Cora-
coid Process of tlie Scapula. 10, Serratus Major Anticus after the removal of the Ob-
liquus Externus Abdominis. 11, External Intercostal Muscle of the Fifth Intercostal
Space, 12, External Oblique of the Abdomen. 13, Its Tendon. The Median Line is the
Linea Alba. — The Line to the Eight of the Number is the Linea Semilunaris. 14, The
portion of the Tendon of the External Oblique, known as Pouparfs Ligament. 15, Ex-
ternal Abdominal Eing. IG, Eectus Abdominis. The "White Spaces are the Linea Trans-
A-ersffi. 17, Pyramidalis. IS, Internal Oblique of the Abdomen. 19, Common Tendon
of the Internal Oblique and Transversalis. 20, Crnral Arch. 21, Fascia Lata Femoris.
22, Saphenous Opening. The Crescentic Edge of the Sartorial Fascia is seen just above
fig. 22, and the Interior or Pubic Point of the Crescent is known as Iley's Ligament.

itself to the front part of the lesser trochanter process of the
femur. It is made up of a very compact band of fibers, and,
though acting at a great mechanical disadvantage, it is ca-
pable of moving the lower extremity with great power. By

6*

128

HITCHCOCK'S ANATOMY

this muscle it is that the "bodj is bent forward when the thigh
is fixed, and also bj its means we keep the body erect when
in a sitting posture.

253. Gluteus Muscle— A

Fig. 143.

A Yicw of the Muscles on the Front of
the Thigh. 1, Crest of the Ilium. 2, Its
Anterior Superior Spinous Process. 3,
Gluteus Medius. 4, Tensor Vaginae Fe-
rnoiis. 5, Sartorius. C, Ilcctus Femoris.
7, Tastus Externus. 8, Vastus Internus.
9, Patella. 10, Iliacns Internus. 11, Psoas
Magnus. 12, Pectincus. 1-3, Adductor
Longrus. 14, Adductor Magnus. 15, Gra-
cilis.

movement in a direction oppo-
site to the last muscle, is ef-
fected by the contraction of
the Gluteus muscle. This
has its origin and insertion at
points directly opposite to
those of the psoas muscle —
and forms the nates or but-
tock. The fibers of this mus-
cle are the coarsest of any in
the whole body, showing that
they are designed for strength
and not celerity of motion.
Besides the movement already
mentioned, this muscle is of
great value when the leg is
made firm by keeping the
body in an upright position,
or raising the body upon the
thighs when it is bent forward.
254. Muscles of the
Thigh.— The leg (Tibia) is
moved upon the thigh (Fe-
mur) by the conjoint action
of four muscles. These have
their orio;in about the head of
the femur, and the lower por-
tion of the innominatum, and
all unite into one tendon
which is inserted,. iippn . the
tubercle, or process of the

What movcracnts arc effected by it? 2o-L What muscle produces motion in a con-
trary direction to the psoa^ muscle ? What is said of tho size of tho fibers of the Gluteus ?
254. now many muscles act to extend the tibia or the femux?

AND PHYSIOLOGY. 129

tibia near to its upper extremity. Spoken of together, these
muscles are called the Quadriceps Extensor Femoris. The
tendon is one of the strongest in the body, and has inclosed
within it the patella, which bears the same relation to the
tendon as the pulley does to the cord which passes over it.
The action of these muscles extends the leg, as in Avalking,
running, or lifting the foot, and also places the femur in a line
above the tibia, when the latter is made the fixed point.

255. Sartorius Muscle. — The Sartoriaa or Tailor's mus-
cle is a very long and slender muscle commencing at the an-
terior portion of the innominatum, and, descending downwards
and inwards, is inserted into the upper part of the inside of
the tibia. The obvious action of this muscle will be to bend
the leg somewhat backwards, and then to carry it across its
fellow, as is done by the tailor when seating himself for work
on his bench.

256. Tensor Yagino) Femoris. — A muscle already alluded
to— the Tensor yagina3 Femoris, or stretcher of tbo sheath of
the thigh — arises at the upper and front portion of the inno-
minatum, and is inserted into the very strong fasciss of the
thigh, its use being to assist the muscles in their action, by
increasing the tonic pressure upon them.

257. Muscles of llie Posterior Part of the Tliigli.—
The muscles found upon the posterior part of the femur
and antagonizing the compound muscle in front, arc four in
number, taking their origin from the ischium and pubes, ar.d
being inserted into the broad head of the tibia. Their ten-
dons make those portions of the thigh which arc familiarly
known as the ham-strings. Their names arc the Biceps,
Gracilis, Semi-tendinosus and Semi-membranosus.

When taken togatlicr, what is tho musclo called ? What bone is iinbeddecl in the ten-
don of the Quadriceps Extensor Femoris? 255. Describe the Sartorius or Tailor's mus-
cle. 253. What is tho Tensor Vaginjs Femoris of service for? 2ol. IIow many muscles
act as antagonists to tho Quadriceps, etc ? Give their names.

130

HITCHCOCK'S ANATOMY

Fig. 145.

A Yiew of the Muscles on the Bcack of
the Thigrh. 1, Gluteus Medius. 2, Glu-
teus Magnus. 8, Fascia Lata covering the
Yastus Externus. 4, Long Head of the
Biceps. 5, Short Head of the Biceps. 6,
Semi-Tendinosus. 7, 7, Semi-Membranosus.
8, Gracilis. 9, Edge of the Adductor Mag-
nus. 10, Edge of the Sartorius. 11, Pop-
liteal Space. 12, Gastrocnemius.

A Yiew of the Muscles on the Front of
the Leg. 1, Tendon of the Quadriceps
Femoris. 2, Spine of the Tibia. 3, Tibi-
alis Anticus. 4, Extensor Communis Digi-
torum. 5, Extensor Proprius Pollicis. G,
Peroneus Tertius. 7, Peroneus Longus.
S, Peroneus Brevis. 9, 9, Borders of the
Soleus. 10, Portion of the Gastrocnemius.
11, Extensor Brevis Digitorum.

258. Muscles of the Anterior Part of the Leg.— Upon
the anterior portion of the Tibia, or leg proper, are found four
muscles with slender tendons, which are for the upward moYe-
ment or flexion of the foot. Thej have their origin near the
head of the tibia, and are inserted into the bones of the meta-

253. Where are the four musdcs located that bend tho foot upward '
aod insertioQ.

Give their origin

AND PHYSIOLOGY.

131

tarsus and phalanges. Their
names are the Tibialis Anti-
cus, Extensor Longus Digi-
torum, Peroneus Tertius, and
Extensor Proprius Pollicis.

259. Muscles of tlie Pos-
terior Part of the Leg.— The
muscles on the reverse por-
tion of the leg are three, con-
stituting what is known as the
calf of the leg. They are the
Gastrocnemius, Plantaris, and
Soleus. They are attached to
the top of the tibia on its pos-
terior side, as well as to the
lower part of the femur, and
all form a conjoint tendon, the
largest in the body, and which
is attached to the bone of the
heel. It is called the tendon
of Achilles, because the great
Grecian warrior is said to have
been killed by the wound of
an arrow at this point. The
use of these muscles is to raise
the body upon the toes, and
are the muscles which are of
the greatest value to us in the
act of walking. Immediately
beneath these muscles are six
an opposite direction to those
leg. They are attached near
fibula^ and inserted into the

Fig. 146.

A Vipw of the Muscles on the Back of tha
Leg. 1, Tendon of the Biceps. 2, Inner
Hamstring Tendons. 3, Popliteal Space.
4, Gastrocnemius. 5, Soleus. 6, Tcndo-
Achilles. 7, Its Insertion on the Os Calcis.
8, Tendons of the Peroneus Longus and
Brevis. 9, Tendons of the Tibialis Posti-
cus and Flexor Longus Digitorum behind
the Internal Malleolus.

others which produce motion in
upon the anterior portion, of the
the upper part of the tibia and
metatarsal bones and the pha-

259. State the muscles which constitute the calf of the leg. T\'hat ij Tendon of Achil-
les, and why is it so called ? IIow many muscles lio deeply covered ia the calf of the

133

HITCHCOCK'S ANATOMY

langes. In the tendon of one of them (Peroneus Longus) is
found a sesamoid bone, at the point where it glides over the
cuboid bone.

260. Muscles of the Fool. — A few muscles are found
upon the upper and under surface of the foot, most of which
Pj^ j4^Y arise near the tarsus, and are

inserted at the base of the
phalanges. In their action
the toes are either bent or
extended.

261. Annular Ligaments.
— An interesting contrivance
for preserving the slenderness
of the hand and foot is found
in the Annular Ligaments.
These are large bundles of
ligamentous tissue which pass
around the wrist and ankle,
ver J much resembling a brace-
let. (Figs. 148, and 149, p.
183.) Thej are very firm and
stout, and their design is to
keep in place the tendons
which move the extremities.
When, for example, we move
the toes upwards, the muscles
which effect this motion with
their tendons would extend in a straight line from the upper
part of the tibia to the last phalanx, thus making the leg
and foot very cumbersome and unwieldy organs, and poorly
adaptecl to their present use.

A Yie-w of the Muscles on the Sole of the
Foot iiTiinetliately under the Plantar Fas-
cia. 1, Os Calcis. 2, Section of the Fascia
Plantaris. 3, Abductor Pollicis. 4, Ab-
ductor Minimi Digiti. 5, Flexor Erevis
Dicritoruin. G, Tendon of the Flexor
Longus Pollicis. 7, T, Lumbricales.

2C1. What is the use of the Annular Ligaments ? What ornamcats do they very closely
icscmble ? Suppose thcso or their equivalent was wanting ?

AND PHYSIOLOGY.

133

Fig. 148.

Fig. 149.

A View of tlie Outer Layer of Muscles
on the B<ack of tlie Fore-Ann (Extensors).
], Lower portion of the Biceps Flexor. 2,
Tart of tbeBracliialis Iiiterniis. 3, Lower
pnrt of the Triceps Extensor. 4, Supinator
Kiulii Longus. 5, Extensor Carpi Eadialis
Longior. 6, Extensor Carpi Radlalis Bre-
vior. 7, Tendinous Insertions of these two
Muscles. S, Extensor Communis Digito-

rum. 9, Portion of the Extensor Communis Digitorum called Auricularis. 10,
Extensor Carpi Ulnaris, 11, Anconeus. 12, Portion of the Flexor Carpi Ulnaris.
13, Extensor Minor Pollicis, The Muscle nearest the Figure is the Extensor Ossis
Metacarpi Pollicis. 14, Extensor Major Pollicis. 17, Posterior Annular Lig.ameDt.
The distribution of the Tendons of the Extensor Communis is seen on the backs of
the Fingers.

A View of the Muscles on the Front of
the Leg. 1, Tendon of the Quadriceps
Femoris. 2, Spine of the Tibia. 3, Tibi-
alis Anticus. 4, Extensor Communis Digi-
torum. 5, Extensor Proprius Pollicis. 6,
Peroneus Tertius. 7, Pcroneus Longus.
8, Peroneus Brevis. 9, 9, Borders of the
Soleus. 10, Portion of the Gastrocnemius.
11, Extensor Brevis Digitorum.

134

HITCHCOCK'S ANATOMY,

FUNCTIONS OF THE MUSCLES.

Fig. 150.

a

262. Irritability of Muscular Fiber.— Muscular fiber has
one characteristic peculiar to this tissue. This is known as
Irritability or Myotility, the shortening of the fiber when a
stimulus is applied. The stimulus may be mechanical, as
when the legs of a grasshopper are irritated with a probe or
some pointed instrument, it produces contractions. Electric
and galvanic currents, also, when made to pass interrupt-
edly through any muscular portions of the body produce con-
tractions ; as when a person grasps the handles of an electro-
tome or seizes the ball of a Ley den jar. And lastly, vitality
is a muscular stimulus.

263. Condition of the Fibrils in a State
of Contraction . — Formerly it was supposed
that muscular contractions were due to a
zig-zag position which was assumed by the
fibrils ; but ni::roscopical examination has
proved that the shortening of the fiber is
owing to a change in the diameter of the
ultimate fibrils ; the cell in the fibril at
rest having its longest diameter parallel to
the fiber, while in a state of contraction the
longest diameter is at right angles to this.

264. Tonicity. — Another characteristic
of muscular fiber is Tonicity. This is a
constant strain or stretch of the muscular
fiber, while irritability or contractility only
manifests itself when a stimulus is applied.
This is a property which is exhibited when
a bone is broken or some muscular fibers

I

1

■

1

■
■

1

1

1

H

1

■

1

■1

1

■

1

■J

structure of the Fi-
brillse. fl, A fibril in
the state of ordinary re-
laxation. 6, A fibril
partially contracted.

are separated.

Thus, when a cut is made

262. What i» the prominent characteristic of muscular tissue? Illustrate the mechan-
ical, electric, and vital stimuli. 263. How do the cells of the fibrils arrange themselves
during a contracted stato? 261. What is understood by Muscular Tonicity? When is
this only manifest ?

AND PHYSIOLOGY. 135

directly across the fibers the gash at once opens very widely ;
or if a bone is broken and the ends allowed to slide by each
other, it is only by great force that they can be brought back
to their proper places. The value of this property is seen in
keeping the muscles in a state ready for action, as well as in
assisting the ligaments to keep the joints firmly together.

265. Dependent on Vital Energy.— Both of these charac-
teristics are dependent upon nervous or vital energy. For if
life be extinct, or the nerve proceeding to any muscle be cut
off, tonicity and irritability soon cease ; although they remain
for a longer time in the involuntary than the voluntary mus-
cles. As, for example, the heart of a sturgeon, after its re-
moval from the body, has been known not only to pulsate for
a short time, but even to keep up its action until its folds
fairly rustled from inherent dryness.

266. Muscular Waste the Cause of Muscular Contrac-
tion.— But here the question meets us. What is this power that
passes through the nerves to each fibril, and how does it energize
the muscle ? Is it a fluid acting on the fibers in the same manner
that water acts upon the strands of a rope, or is it an impon-
derable agency, like electricity or heat, passing through the
nerve by polar attraction or conduction from particle to par-
ticle ? At present we must rest with the facts of muscular
movement, and perhaps we can never solve the mystery in
this world. The nature of what we vaguely denominate
nervous or vital force has never been determined. iSTo mys-
tery in religion exceeds that of muscular movement. It how-
ever seems to be the case that muscular contraction is in a good
degree dependent on a due degree of arterialization of the
blood ; for if a muscle be placed in carbonic acid its irritability
soon ceases, while in oxygen it remains a long time after it is
removed from the body. A want of the proper amount of oxy-

Of -what use is this property ? 265. Upon what do both myotility and tonicity depend ?
In which muscles do they remain the longest after death ? Instance the heart of the stur-
geon. 266. What is all we know of the power that produces this contraction ?

136 HITCHCOCK'S ANATOMY

gen is the cause of the inability to exertion experienced in the
thin air of mountain tops and the relaxation of the muscles in
fainting from exposure to carbonic acid, ether, or chloroform.
On the other hand, the more full the respiration, tbe more ener-
getic the muscular power. The effect of oxygen upon the tis-
sues is that of waste, or a consumer ; that is^ it produces a more
rapid circulation of matter by removing the carbonic acid,
and substituting itself in its place ; and the deeper the respi-
ration, the more energetically will all the functions of the
body be carried on. Hence a plausible theory offers itself
to explain the cause of muscular contraction, which is, that
' ' muscular contraction is the necessary physical result of mus-
cular disintegration. ' '

267. The Mechanical Disadvantage at which many
Muscles Act — The Reason of it. — The force of muscular
contractions is almost always very great, sometimes so pow-
erful that some of the fibers are ruptured. But the main
evidence of this great force is exhibited in the mechanical dis-
advantage at which most of the muscles act. For instance,
Fig. 151. if the muscles were

attached at c, a much
greater weight could
be lifted by the ex-
penditure of the same
power than if it were
attached at b ; but a much longer portion of time would be
necessary to produce contraction in such a length of fiber, a
c, than in a shorter portion, a b. Besides, in most cases it
would be quite impossible for the muscles to contract suffi-
ciently to effect what they now do, since muscular fiber can
not shorten itself more than one third of its whole length, as
measured when uncontracted, or in a state of rest.

What, however, do we know about deficiency of oxygen as aflfecting these properties?
Instance ether and chloroform also. What hypothesis has been suggested owing to tho
waste produced by oxygen ? 2G7. IIow is muscular power well illustrated? What los3
and what gain are both experienced by this construction ?

AND PHYSIOLOGY. 137

268. Contraction commences at one End— Only a Part
of the Fibrils in a State of Contraction at Once. — The
contraction of a muscle does not take place in all parts of the
fibers at the same time, but commences at one end, and con-
tinues through in regular yig. 152.

order, as is seen in the
cut 152. It is also sel-
dom the case that all the
fibers are contracted at
once. This explains the
reason why insane people

^, , . . , Muscular Fiber contracting, a, Uncontracted

are Otten so prodigiously part. &, Contracted part.

Strong, since the whole of the muscle is made to act at once.
It also shows us why we can keep a muscle contracted for a
long time, as in carrying a weight for a long distance, and
also why a short and violent muscular action weakens and
tires us more than a protracted and more moderate one. The
simple explanation is, that but a part of the fibrils are con-
tracted at once, and when the nervous force is exhausted from
one set of fibrils, a new set are called into action to supply
their power.

269. Examples of Muscular Strength.— As examples of
great muscular strength, we have given to us the history of a
Samson and Goliath. And in more modern times we read of
Milo of Crete who killed an ox with his fist, and then carried
it more than 600 feet. He also saved the life of his fellow-
scholars and teacher, Pythagoras, by supporting the falling
roof until they had time to escape. Another man is men-
tioned who could raise 300 pounds by the muscles of his lower
jaw. This strength, however, is exhibited much more strik-
ingly in another part of this chapter under the head of Com-
parative Myology.

268. Do all the fibers, or even all portions of each fiber act at once in ordinary cases ?
Instance insane people. 269. Give examples of great muscular strengh as illustrated hj
Goliah and Milo.

138 HITCHCOCK'S ANATOMY

270. Rnpidity of Muscular Contraction.— The rapidity
of muscular movement is equally wonderful. The pulsations
of the heart in children can often be counted as high as 200
per minute. Some persons can pronounce 1500 letters in a
minute (of course combined in words), each one requiring the
contraction and relaxation of one or more muscles, and both
occupying ^ Aoth of a minute, or ^Vth of a second. The
muscles, too, which move the wings of some insects must
contract many thousands of times every second in order to
produce the musical tone or humming that is frequently heard
when their wings are in motion.

271. Duration of Muscular Contraction — Intrinsic and
Available Force — Shortening of Musfcular Fiber— Muscu-
lar Sense— Sound and Heat.— The length of time which
muscles may be on the stretch is astonishing, but especially
so among the lower orders of animals soon to be mentioned.

The intrinsic force of a muscle is no measure of its avail-
able power. Thus the deltoid, if able to act in a perpendicu-
lar direction, would raise 1000 pounds ; while, acting at the
great mechanical disadvantage (that it does) of passing over the
head of the humerus, it can not lift 50 pounds held in the
hand.

The amount of shortening of the fiber in muscular contrac-
tion is differently stated by physiologists. The statements
are from one third to one sixth the length of the muscle.
That is, a muscle three inches long can by contraction be-
come only two inches, or one six inches long become five
inches. It is probable, however, that the former statement is
the nearest to the truth, and that a muscle is shortened from
one half to one third its orio-inal leng;th.

The muscles give but little evidence of sensibility ; that is,
perception of objects by pressure or touch ; but when fatigued oi^
overworked, they give a painful sensation, and also give to iheii

270. State instances of great rapidity of muscular movement, as in pulsations of
children's hearts and the power of articulating words. 271. State the distinction be'
tween the intrinsic and available force of muscles. How much does muscular fibel
eborten during its contraction ? What is muscular sense ?

AND PHYSIOLOGY. 139

possessor a very delicate sense of the amount of their contrac-
tions.

It is also an established fact that a peculiar rumbling sound
is given off and heat evolved during muscular contraction,
the latter of which is easily explained by the increased mus-
cular waste, or the absorption of oxygen and evolution of car-
bonic acid.

272. Prceision of Muscular Contraction. — An astonish-
ing precision in contraction of muscles is seen in those of the
human larynx. The largest of these muscles is less than
three fourths of an inch, and the total amount of contraction
one fifth. And since the ordinary compass of the human
voice is two octaves, or twenty-four semi-tones, and ten inter-
vals between each of the contiguous semi-tones can be easily
detected by a person with a cultivated ear, there must be a
shortening of only y 2V o th of an inch. And more wonderful
than all is the precision and readiness with w^hich an ordinary
singer can accurately strike one note after another with inter-
vals of from two to twenty-four semi-tones.

HYGIENIC INFERENCES.

273. — 1. Muscles need Use .—The muscles should be used.
This is necessary to stimulate the blood-vessels and lymphatics
to . a healthy action, so that the nutritious particles may be
deposited in proper proportion, and the waste particles be re-
moved ; in other words, to promote that constant change
which in all the organs of the body is so necessary for health.
Their moderate use also promotes their growth and strength,
while inaction causes them to diminish both in strength and
size.

Speak of sound and heat attendant upon muscular contraction. 272. What remarkable
precision is there in many muscular movements? 273. Why Is It necessary that the
muscles be used to a moderate extent ?

140 HITCHCOCK'S ANATOMY

274. — 2. Muscles need Rest.— The muscles also need rest.
That is, after work they need repose to restore the energies
which thej have expended, and if the amount of rest which
they receive is not sufficient to recruit the strength, they will
soon become small and weak ; for the lymphatics are so stimu-
lated that the amount of matter removed exceeds what is de-
posited. But sleep is the grand restorative after severe mus-
cular exertion ; this alone gives back to the muscle its life
and strength.

275. — 3. Muscles should Rest gradually after Yloleut
Ex or else. — Experience, however, shows that when the mus-
cular system has been exercised vigorously it should not be
allowed perfect rest at once, but by degrees. Such a course
would save many an ache sjid stiiF joint to the hard-working
farmer and mechanic, and especially to the one who labors
till the body is in a state of perspiration.

276. — 4. Muscles require Regular Exercise. — Labor or
exercise that is regular and uniform is much the most conducive
to health. The muscles will endure a much greater amount
of effort if made steadily, rather than spasmodically. Regu-
larity of action is important in every function, but in none
more evidently so than the muscles.

277. — 5. Especial want of Exercise by Students and
Sedentary People. — We see that students and other seden-
tary persons are in special need of physical exercise, and
should consider it a moral duty to secure it, for it stimulates
every organ to a healthy action. The blood flows more
readily, and m.ore completely fills all the minute vessels ; the
glands of the skin act more vigorously ; the lymphatics and
nutritive vessels perform their part more perfectly ; and even
the nervous system is kept in a healthy state by exercise. It
is best, however, to get exercise if possible with some other

274. For ■\vhnt do the mnsclos of hard-working men need rest, and especially sleep ?
275. Is it always best to gain rest at once, or gradually ? 276. What kind of labor or ex-
ercise is most conducive to health? 277. V/hy do students and sedentary peoplo stand
greatly In neod of muscular exertion ? Is mere drudge v/ork the best exercise ?

AND PHYSIOLOGY

141

motive than a mere conviction of its necessity and importance.
For if we are interested in pursuing an object, the mind ac-
quires a healthy action, and by its reaction brings on a state
of perspiration in the body. In this case we have obtained
two ends, the muscular system has been exercised, and the
mind has gained full recreation from study. Hence the study
of natural history, and especially those branches of it which
require field exercise in collecting specimens, not only
strengthens the mind and furnishes ncAV objects of thought,
but is an admirable method of gaining bodily strength.

278.— 6. Value of Gymnasia, etc., to Colleges and Acad-
emies.—We see how injurious to health is the stimulating
plan adopted in too many of our higher seminaries of learn-
ing. The mind is crowded to its utmost with labor ; too
much time is taken up with cultivating the intellect, while
the body is left to take care of itself A gymnasium or
some equivalent means of taking exercise is as important
a thing to our colleges and academies as are the build-
ings, libraries and cabinets themselves. And may it not
be the reason why literary men are generally so great suf-
ferers from ill health, that so little attention is paid to physi-
cal culture during the preparatory and collegiate course?
Is it not poor economy to take so much pains to cultivate the
inhabitant, when the house that it is to live in is such a mis-
erable tenement, anil receives so little care and improvement ?

KEMARKS UPON MUSCULAR DEVELOPMENT.

AYith the existing customs of the wealthier clashes of
Gocicty, and our higher seminaiies of learning especially, it is
hardly possible to say tjo much upon the necessity of physical
education : not that it is best to lower the standard of intel-

Why does the study of some branch of natural history secure the best exercise? 278.
What is said of the effect of a neglect of musculai* exercise in schuols and upoa many
educated men of our country?

142 n ITCH cock's anatomy

lectual culture in. the least, cr to dictate liow tliose wl:o are
possessed of an abundance of wealth shall dispose of it, but
simplj to say that a thorough physical education is essential
for a proper enjoyment and improvement of our Tvhole nature,
body, mind, and soul. The evils of a neglect of this branch
of education exhibit themselves, not only in puny clergymen
and lawyers, but in the meager and attenuated physiques of
our mothers and sisters.

Boys, especially wlien boys, will run, jump, shout, ar.d
be in the open air in spite of any thing but the closest
watch ; in flict it is thought proper that boy 3 should ba ruddy
ill countenance and healthy, but with girls it is not so.
By grossly perverted usages of society, it is considered im-
'proper for girls to run and jump and shout, and especially so
out of doors ; but while mere children even, they must act as
young ladies^ and never move except in a precise and meas-
ured manner, often as unnatural as it is injurious ; and any
thing that requires muscular effort, is regarded as vulgar,
and of course not to be undertaken. Now, physiology tells
us that just the thing which our girls and ladies stand
in need of at the present day is active, vigorous muscular
effort, such as walking, rowing, riding on horse-back, and
calisthenic and gymnastic exercises. And let the question
be suggested to parents, guardians, and in fact all inter-
ested in the prosperity or even the existence of the Anglo-
Saxon race on this continent, whether the physical develop-
ment of ladies shall be neglected through the idle whim of
its impropriety (which often only generates a false mod-
esty or prudishness), and thus tend to a deterioration of
the race which is noAV in fearful progress in the United
States.

Without a proper exercise of the muscles in man or
woman, all the other portions of the body must suffer, and
if so, why, through an over sensitive, prudish caution, must
woman be the unfortunate victim? The old Greeks —
heathen though they were— did not neglect the development

AND PHYSIOLOGY. 143

of the body in either men or women. And while they most
thoroughly disciplined the intellectual powers, their "semi-
nary of learning'' was the gymnasium, where, as prominent
characteristics, were the running, wrestling, and boxing exer-
cises, and by them regardod as equally important with intel-
lectual effort.

But though the neglect of muscular exercise h the most
sadly evident in the female portion of society, yet it is not
confined here. For many of our educated men are of feeble
physical culture, mainly because of the cultivation of the in-
tellect at the expense of the body. Most men in the academ-
ical and professional schools are apt to regard study as first
and foremost, and a care of the body afterwards — if there be
any time for it I How many make it a duty -and a relig-
ious one too — to take all the time that can possibly be se-
cured for study, and leave the exercise as a thing desirable
but not essential ! But we maintain that a system of educa-
tion which simply crowds the mind with discipline, to the
neglect of physical culture, is not only a defective, but a
monstrously pernicious system. Students may bear the
cramming process through the academical, collegiate, and
even professional course, but sooner or later the body will be
overpowered. Nature's laws cannot be violated without suf-
fering the penalty at some time ; and of what service can the
most cultivated minds become, if the body is too feeble to use
their learning? Of what beauty is the most brilliant gem
without the art of the lapidary to develop and exhibit its
splendor ?

In how few educational institutions in our country is there
any thing like a system of exercise suggested, or much more
required ? In how few of them does muscular development
meet with any thing but discouragement ?

It is true that muscular development has for too long a time
among us been associated with the lower class of people, as
prize-fighters, shoulder-hitters, bruisers and horse-racers, in
all which cases it should meet a decided disapproval. But is

7

144 HITCHCOCK'S ANATOMY

this a natural tendency of physical development ? Is it
necessary that a well-developed man must of necessity be a
brutal fighter ? or that a beautiful horse must necessarily lead
his master to expose him to cruel excesses to test his speed ?
If we do adopt the principle that physical development has
such an immoral tendency, is there any culture of body or
mind that we shall not be compelled to resign to the great
tempter, since he can so sadly pervert every thing ?

Ought not then a gymnasium or some equivalent means of
physical culture, to be attached to all our educational institu-
tions (female as well as male), as well as models, libraries,
cabinets, and apparatus ? And if so, why should there not
be regular trainings of the body required by instructors as well
as mental exercises ? And since but a small portion of time
is required for physical exercise if it be vigorous, as it will of
necessity be in a gymnasium, why may not a portion of school
duties each day be a half hour or an hour of exercise in the
gymnasium morning and evening ? Does not every practical
teacher see that at least this would relieve the necessity of a
great many excuses, such as for '' head- ache," ''feel sick,"
" unable to study to-day," etc.
Fig. 153. There are, however, many simple gymnastic ex-
ercises which may be indulged in by everybody,
boys and girls, men and women, without an outlay
of any thing except a few dimes, and the use of a
few yards of space anywhere on terra firma.

From a piece of inch pine board from two to four
feet long (depending on the size of the person to
S, y use it), and three to six inches wide, let an instru-
ment be made called the hack board^ as is shown
in Fig. 153. With this simple piece of apparatus
grasped at each end, as in Fig. 154, a great va-
riety of exercises can be invented by any one, which will soon
set the whole surface in perspiration, and if persevered in
will, in the course of several days, impart pliancy and strength
to the muscles.

AND PHYSIOLOGY.

145

Fi(^- 154. A more vigorous exercise can Fig. 155.

be obtained by using what is
termed the " Indian club," or
" scepter," one in each hand.
(See Fig. 155.) These may be
made by the commonest turner
from any sort of wood, and it
is well that there be several
pairs of them, differing in weight
and length, and loaded with
lead if necessary, adapted to
the age and muscular development of
those using them. And it is astonish-
ing what great strength of muscle can
be acquired by this means of exercise
continued through a few weeks. Some

of the different exercises which may be performed with this

club may be seen in Fig. 156, p. 146.

Another simple mechanism for gaining physical exercise,

called the '' triangle," is seen in Figs. 157 and 158. It is

Fig. 158.

Fig. 157.

146

HITCHCOCK'S ANATOMY

FlQ. 156.

AND PHYSIOLOGY.

ui

Fig. 159.

made by hanging a bar
between the ends of two
ropes twisted together,
as in Fig. 157, or from
two ropes hanging per-
pendicularly from the
ceiling. This triangle
may be suspended from
the ceiling of any room,
or the branch of a tree,
and is of great service
for exercise, since it
calls into use not only
the upper, but also the lower extremities.

But much more complete exercise, and that which tends to
give symmetry of form to either sex, may be obtained from

148

HITCHCOCK'S ANATOMY

Fig. 160.

AND PHYSIOLOGY

149

Fig. 161.

150

HITCHCOCK'S ANATOMY

the various appurtenances of the gymnasium. Here, b/
means of bars, ladders, ropes and similar pieces of appara-
tus are the best arranged contrivances, not onlj for a gen-
eral exercise of the whole body, but for developing the most
important muscles. A few pieces of this kind of furni-
ture may be seen in Figures 159, 160, and 161. These
may be fitted up in any larie and unfurnished building,
since the essential requisites are a few solid timbers to
give firm support to the bars and ladders, and walls mainly
to protect from exposure to severity of weather.

The exercise of rowing is one which probably can not be
surpassed as a means of exercise, since it not only requires a
use of the muscles, but is exhilarating and recreating to the
spirits ; and where circumstances admit, whether as supple-
mentary to or in place of a gymnasium, we would say by all
means let both boys and men, and ladies too, indulge in the
invigorating and healthful exercise of boat rowing.

COMPARATIVE MYOLOGY.

279. In microscopic structure the muscles of the lower
orders of animals very closely resemble those of man, as may
be seen in the fibrils of the pig, Fig. 162.

280. Tegument ary Muscle— Abdominal Muscles— Mus-
cles of Lower Jaw — Diaphragm.— The general structure
and relations of the muscles in quadrupeds differ very little
from those of man save in the extremities. Nearly all quad-
rupeds have a set of fibers called the Tegumentary Mus-
cle, which is a thin layer of muscle lying just beneath the
skin, and which is only rudimentary in man. Its func-
tion is to contract and corrugate the skin in order to remove
dust, insects, or any offending matter, as can be seen in a

279. What is said of tho structure of muscles In all mammals ? 2S0. Describe tlio
Tegumentary Muscle

AND PHYSIOLOGY.

151

Muscular Fibrils of the Pig. a. An ap-
parently single fibril. & c, Collections of
fibrils.

horse or cow during the time ^i*^- 1^2.

•when flies irritate by biting.
The same muscle in the por-
cupine and armadillo is made
use of to roll themselves up in
a ball. In apes the foot and
hand are similar both in mus-
cular development and func-
tion, but are by no means
equal to the hand of man.
The abdominal muscles of all
quadrupeds are stronger than
man's, since from their posi-
tion the weight of the viscera
is thrown upon the muscular
walls of the abdomen, and
not upon the bones of the pelvis, as in him. In beasts of
prey the masseter and temporal muscles are more strongly
developed than in man, because great strength is required
in the jaw to secure the food and fit it for digestion. In all
mammals a more or less complete diaphragm is found, though
it is absent in nearly all the remaining yertebrata.

281. Muscles of Birds— Ossification of Tendons.— The
muscles of most birds are remarkable for their deep red color
and the density of their structure. In herbivorous ones, how-
ever, they are of a paler color and softer in texture, and hence
more palatable as articles of food. The bellies of the muscles
are for the most part situated on the body, so that they may
not encumber the limbs ; and those designed to move the ex-
tremities are extended into long tendons, which, as already
mentioned, become ossified to a considerable extent.

Of what use is this muscle in the porcuinne and armadillo? Why are the abdominal
muscles of quadrupeds proportionally stronger than in man? What is said of thestrensth
of the masseter and temporal muscles of beasts of prey ? What of a diaphragm ? 2S1.
What are the muscles of birds remarkable for ? What is said of the tendons and belliei
of mnseles In birds ?

•7*

152 HITCHCOCK'S ANATOMY

282. Suspensory Muscle .—In the turkey and birds of like
character an especial muscle is provided for the support of
the crop, which so often becomes heavily loaded with food.

283. Muscles of Birds' Feathers — Their Use— Their
Number — Muscles of the Breast. — Birds are supplied with
tegumentary muscles somewhat after the manner of quadru-
peds. The main diifference is, that in birds a few muscular
fibers are sent to each quill feather of the body, by which the
feathers can be violently shaken to dislodge dirt, or they may
be merely raised on end by the same muscles. This property
is well seen in common barn fowls, when they shake them-
selves after having lain in dry dirt. A hen with a brood of
chickens, too, when disturbed shows her wish to protect her
young by ruffling up her feathers and attacking whoever may
annoy her. In some birds, where there are 3,000 quill feath-
ers, the number of muscles must be at least 12,000. No
muscles are found upon the face of birds, but to secure the
degree of motion to which the head is subject, and the flexi-
bility of the neck, the muscles of this portion of the body are
very strongly developed. The most powerful muscles of
birds are the pectoral, or those on the breast ; one end of
which is attached to the keel of the sternum and the other to
the humerus. These muscles are three in number on each
side, and the largest one exceeds in weight all the other mus-
cles of the body.

284. Muscles of Fishes. — The muscles of fishes are char-
acterized by their slight degree of separation from one an-
other, by the absence of long tendons, and the softness of their
fibers. Their color is generally white, or yellowish white,
but in microscopic structure they do not differ from those of
the other vertebrata. By far the largest part of the fleshy

282. What peculiar muscle is found In birds like the turkey ? 288. What is worthy of
note in the tegumentary muscle of birds? In what condition does a hen show the ac-
tion of the tegumentary muscles ? What number are there in some birds? Why is
there need of so few muscles on the head of birds? . Upon what portion of the body are
there the most muscles? Give the actual am6unt by weight 284. What is tbe peculiar
feature of the muscle of fishes? Give their color.

AND PHYSIOL O GT

153

mass of these animals is made up of the lateral muscles of
the bodj which extend from the head to the caudal fin ; and
as each lateral muscle by its contraction bends the body to its
own side, the motion of the fish through the water is effected
in the same manner as the oarsman sculls his boat.

Fig. 163.

Muscular Fiber from Leg of Meat Fly, a, Termination of Muscular Fiber, t, Tendon.

285. Muscles and Locomotive Organs of tlic Inverte-
brates.— Muscles, both striated and smooth, voluntary and
organic, abound in all the invertebrates. They are modified
in form and position to meet the wants of the animal as wisely
as in the higher tribes. Fig. 164.
In some of the Polypi
movements are made by
the contraction of their
sides, in which no mus-
cular fibres have been
discovered, though ex-
existing in other parts

of the animal. The insect Fasciculi Magnified Fifty Diameters.

muscles of insects are either colorless or of a dirty yellow.

286. A great variety of locomotive organs are found in the
Invertebrates. The Echinoderms have tentacles, called Am-
bulacra, on some of which there are suckers, which enable
them to bold on to substances. They have also forcep-like
organs of locomotion. Most of the acephalous molluscs move
by a highly developed foot, which, in the Cephalopoda, is used
as a sucker. The Cephalopods have arms with suckers at-

What portion of the Iwdy is made up of them? 28G. What are the locomotive organs
of Invertebrates?

154 HITCUCOCK'S ANATOMY.

tached to the cephalic cartilage. Annelids move by sub-
cutaneous muscles, stings, and bristles. The Rotatoria re-
volve by a retractile vibratile apparatus. Crustaceans have
usually two legs to each segment, and the Myriapods some-
times four. Some of these appendages are tactile, some for
oars, and some ambulatory. Spiders have four pairs of legs,
and insects three.

287. Examples of Muscular Strength.— There are some
remarkable examples of muscular strength among the lower
animals. A flea harnessed will draw from seventy to eighty
times its own weight, while a horse can not draw more than
six times his weight. The flea weighs less than a grain, and
will clear several feet at a leap. The common dorr bettle,
weighing but fifteen grains, has been known to heave a weight
placed upon him amounting to 4.769 grains, equal to nearly
320 times his own weight.

288. Length of Time the Muscles can be Employed.
— The length of time during which some muscles can be em-
ployed without rest is also very remarkable. Many birds will
fly uninterruptedly for hundreds of miles, and it is also said
that insects will remain suspended in the air a whole sum-
mer's day without alighting.

289. Rate of Flight of Birds.— Some birds fly sixty
feet in a second ; but a race-horse scarcely ever exceeds forty
feet in the same time. A falcon of King Henry II. flew on
one day from Fontainbleau to Malta, a distance of about
1,000 miles. The rice-bird, which afterwards becomes the
reed-bird of Delaware Bay and the bobolink of New York, is
often found below Philadelphia with green rice in its crop.
The same thing is true of pigeons during the rice-growing
season.

287. State the power of a flea compared with a horse. 28S. What is wonderfal about
the length of time that some insects can tise their muscles without weariness ? 289. Witk
what speed can some birds fly? <xive the instance of King Henry's falcon.

CHAPTER THIRD.

THE NUTRITIVE SYSTEM.— SPLANCHNOLOGY, OR HISTORY
OF THE DIGESTIVE ORGANS.

DEFINITIONS AND DESCRIPTIONS.

290. Definition of Digestive Organs. — The Digestive Or-
gans are those which receive the food into the body and effecl;
such changes in it that the various tissues can be formed
from it by means of the glands. Of these organs the princi-
pal one is the Alimentary Canal. This commences with the
mouth, and includes the stomach, with the whole length of
tube known as the intestines. This canal, in a full-grown
man is about thirty feet in length, being as a general rule
five times the height of the individual, and is lined through-
out its entire length by mucous membrane.

291. Tlie Mouth; Salivary Glands; the Tonsils.— The
Mouth contains the organs of mastication including the teeth
and tongue, and receives the saliva, which is secreted by three
pairs of glands named Parotid, Submaxillary, and Sublingual,
situated just beneath and behind the lower jaw. Besides
these three glands there are many other minute glands and
follicles situated upon the floor and backsides of the mouth,
which secrete fluids that aid in mastication and digestion.
The Tonsils are simply an aggregation of follicles situated in

290. What firo Di£restire. Organs? Give the general clescription of the Alimentary
Canal. 291. What does the mouth contain ? Name the three principal pairs of glands
and give their location.

156

HITCHCOCK'S ANATOMY

Fig. 165.

A View of the Salivary Glands in situ. 1, The Parotid Gland in situ and extend-
ing from the Zygoma above to the Angle of the Jaw below. 2, The Duct of Steno.
S, The Sub-Maxillary Gland. 4, Its Duct. 5, Sub-Lingual Gland.

Fig. 166. tlie upper part of the

fauces or throat, a few
of which are represent-
ed in Fig. 166. The
mouth is a variable cav-
ity having no emptj
space within it when
closed, and when fully
open, containing nearly
half a pint.

292. The Pharynx.—

The Pharynx (the Greek

name for this portion of

the body) is the next division of the alimentary canal. It is

a short and somewhat irregular tubular cavity, into which

the mouth opens behind, serving as a portion of the canal

What are the Tonsils? Are there any other glands in the mouth? 292. Describe tho
Pharynx.

A feAv Follicles from Human Tonsil.

AND PHYSIOLOGY.

157

Fig. 167.

Pendulous Palate.

Base of the Cranium.

Pharynx.

Esophagus.

Trachea or "Windpipe.

Yertical Section of the Mouth and Throat.

from the mouth to the stomach, its lower limit being nearly
opposite to the Pomum Adami (Adam's apple) in front, and
thie fifth cerYical vertebra behind. It also communicates with
both ears, with the nostrils and lungs, bj passages which open
directly into it. The communication between this cavity and
the mouth may be entirely cut off by means of a movable
muscular curtain called the soft or pendulous palate, which is
of great service in the act of swallowing. This portion of the
alimentary canal is made up of muscular fibers which run in
two directions, so as to cross each other at a large angle, in
order to give the most perfect compression upon the food as
it passes through it. And in its lining (mucous) membrane
are found a great number of follicles or sac-like bodies of
microscopic size called Pharyngeal Glands.

293. Esophagus.— The Pharynx terminates in the Eso-
phagus (meaning the passage for conveying the food). This

What cavities does it communicate with? What is said of its muscular coat? 203.
What is the Esophagus?

ir,8

HITCHCOCK'S ANATOMY

Fig. 168.

Glands of Esophagus Magnified fifteen Times.

is a long and narrow tube, made up of two muscular coats,
which terminates in the stomach by the cardiac orifice. It is
smaller in size than the Pharynx, and contains a grea,t num-
ber of minute glands, (see Fig. 168), which secrete an oily
fluid when the food is passing through it,

294. Stomach, its Coats, its Size, its muscular Coat,

Fig. 169.

Section of Human Stomach. 1, Esophasns. 2, Cardiac Orifico. S, 4, 5, 6, Greater
and Lesser Curves of the Stomach. 7, Dilatation, or rudiment of a Second Stomach.
8, Folds of the Mucous M^jmbrane. 9, Pyloric Orifloe. 10, 11, aad 14, Duodenum.
12, Duct of Pancreas and Liver. 15, Jejunum.

AND PHYSIOLOGY

159

Gastric Follicles. — The Stomach is the largest expansion of
the alimentary canal, situated in the upper portion of the
left side of the abdomen, immediately beneath the diaphragm,
inclining obliquely downwards from the -left to the right. Its
walls are made up of three coats : an outer or serous, a middle
or muscular, and an inner or mucous. Its normal or average
size will allow it to contain about a solid quart, but in gor-
mandizers, and wine and beer drinkers, it is dilated to three
or four times that size. In the middle or muscular coat (Fig.
170) the fibers run at right angles to each other, in order that

A Front View of the Stomach, distended by flatus, with the Peritoneal Coat turned
off. 1, Anterior Face of the Esophagus. 2, The Cul-de-Sac, or greater Extremity.
8, The lesser or Pyloric Extremity. 4, The Duodenum. 5, 5, A portion of the Peri-
toneal Coat turned back. 6, A portion of the Longitudinal Fibers of the Muscular Coat.
7, The Circular Fibers of the Muscular Coat. S, The Oblique Muscular Fibers, or
Muscle of Gavard. 9, A portion of the Muscular Coat of the Duodenum, where its Pe-
ritoneal Coat has been removed.

they may contract in the most efficient manner upon the con-
tents of the stomach for the purpose of digestion, and forcing
the contents onwards into the Duodenum, They also assist
in forcing the contents of the stomach backward in vomiting.
In the inner or paucous lining are situated an immense num-

294. Where is the Stomach situated? What is its normal size? How many coats has
Jt and what are they ? Of what service is the muscular coat ? What glands are con-
tained In the mucous membrane of the stomach ?

160

HITCHCOCK'S ANATOMY

ber of tubular glands which open directly into the stomach.
They are cup-shaped cavities about the 3 5Vo-th of an inch in
diameter, and 4-Vth in length, from the bottom of which pro-
ject two or more parallel tubes, ending in a closed termina-
tion in the tissue beneath. These compose the greater por-
Fig. m. Fig. 172.

Diagram of the Stomach and Intestines. 1, Stomach.
2, Esophagus. 3 and 4, Stomach. 5 and 6, Duode-
num. T, Jejunum. 8, Ileum. 9, Cnecum. 10, Yer-
Uiiform Appendix. 11, 12, 13, 14, Colon. 15, Ecctum.

The Glands in the Coats of the
Stomach, magnified forty-flve dia-
meters. 1, A Gastric Gland, from
the middle of the Stomach. 2, An-
other, of more complex structure,
and appearing to contain Mucus
— from the neighborhood of the
Pylorus.

tion of the mucous mem-
brane, and are for the
purpose of secreting the
gastric juice, and prob-
ably the Pepsin also. In
addition to these glands,
a large number of the
mouths of veins open
into the stomach, which
act the part of absorbent
vessels to remove the
water, whether pure or
mixed with other sub-
stances.

295. Duodenum.—
The first division of the
Intestines is the Duo-

AND PHYSIOLOGY

161

denum, because in length it is equal to the breadth of twelve
fingers. It commences with the pyloric orifice on the right
extremity of the stomach, and runs slightly backwards and
upwards until it terminates in the Jejunum. It is often
called the second stomach, because a certain part of digestion
takes place here, and the food passes slowly and receives no
less than three difierent secretions : one from the Liver, an-
other from the Pancreas, and the third from the LIucous
membrane of the intestine itself

296. Jejunum. — Next below the Duodenum is the Jeju-
num, meaning "empty," since it is always found in this con-
dition after death. This, like the other divisions of the intes-
tine, has three coats, and is of a slightly pinkish color, be-
cause here the mucous membrane is thicker than in any other
of the intestines. Fig. lis.

297. Ileum — The Ileum
(from the Greek signifying
to twist) is the third division
of the Intestines, and is about
fifteen feet in length. It is
the smallest Intestine, and has
a darker color than either of
those already mentioned, and
is exceedingly tortuous in its
course.

298. CsBCum.— The fourth
division of the Intestine is
the Caecum. This is a shut
sac much larger than the
small Intestine, and of a

The Caecum and its Appendix. 1, Cae-
cum. 2, Colon. 3, Ileum. 4, Entranca
from Ileum to Colon. 5, llio-Caecal Valve.
6, 7, 9, Parts of the Appendix Cffici.

What do they secrete ? What vessels open into the stomach, and of what service are
they? 295. What is the Duodenum ? Give its general course. W^hy is it sometimes
called the second stomach ? What fluids are poured into it ? 296. What is the namo
Jejunum derived from? What is its color? 297. How long is the Ileum? What is
said of its shape? 29S. Name the fourth divison of the intestines. Describe it.

162 HITCHCOCK'S ANATOMY

grayish blue color, and not exceeding three inches in length.
The entrance of the Ilium into the Caecum is effected bj a
valvular arrangement which allows the food to pass into the
Caecum, but never in the opposite direction. It is situated at
the right Innominatum in the lower part of the abdomen, and
its lowest portion has a worm-shaped process attached to it,
which is onlj rudimentary, and consequently of no great
service to man, but largely developed and of great service in
some of the lower animals, and especially in the herbivorous
ones.

299. Colon. — The Colon (from the Greek signifying "to
prohibit," since the food passes very slowly through this part
of the canal), commences at the Caecum on the right side of
the abdomen, and in the first part of its course passes in an
upward direction, and is called the ascending Colon. When
it reaches the lower edge of the liver, it crosses horizontally
to the extreme left edge of the body, constituting the trans-
verse Colon. After this it descends, and joins the Rectum,
forming the descending Colon. Its length is from five to
eight feet.

300. Rectum. — The Rectum completes the divisions of the
Intestines. It is nearly straight in its course, of a larger
size than any other division of the canal, except the stomach,
and from six to eight inches in length. Its name is derived
from the straight direction which it assumes.

301. Division of the Intestines into small and large. —
The last three divisions have a much larger diameter than
the first three, and are called on that account the large Intes-
tine, and the Duodenum, Jejunum and Ilium, the small In-
testine. The latter seems to be the portion necessary for
preparing the food to enter the Lacteals, while the large In-
testines act mainly as a receptacle for the waste portion.

Where is its location in the body? What curious appendage is attached to it? 299.
What are the three divisions of the Colon? How long is it? 8D0. What does the Colon
terminate in? How long is the Kectum ? 301. Define the largo and tho small Intestine,
and give their probable uses.

AND PHYSIOLOGY.

163

Fig. 174.
Liver. Pylorus. Gullet. Pancreas

Gall-Eladder.

Large Intestine.,^,

Caecum.

Appendix of the
Caecum.

Stomach.

Spleen.

• Colon.

Small Intestine,
Colon.

Small Intestine.

Eectum.

Digestive Apparatus in Man.

302. Structure of Iiitestiius, Intestinal Glands.— Like
the Stomach, the Intestines are formed by three membranes.
Also in the inner or mucous membrane are situated an im-
mense number of microscopic glands, so that a French teacher
speaks of them existing "■ as numerous as the stars in the
Starr J heavens." They are distinguished as Duodenal Glands,
Brunner's Glands, Solitary Glands, Peyer's Patches, and
Follicles of Lieberkuhn. (Fig. 175, p. 164.) They are
most abundant along the course of the Ileum and they seem
to be especially affected in Typhoid Fever, although no cer-
tain use for them in health has as yet been discovered. The

802. What Is the structure of the Alimentary Tube ? What is said of the Glands found
In Its maeoQS Lining ? State their names.

164

HITCHCOCK'S AX ATOMY

Fig- i'?5. Follicles of Lieberkuhn

are found onlj in the
large intestine. The
Mucous membrane of
this part of the canal,
is not smooth and con-
tinuous with the serous
or outer layer, but is
doubled upon itself in a
great number of folds,
in order that the surface
containing these glands
may be the largest that
is possible, so that the
contents of the Intestine
may receive a large
supply from these secretions. Minute Villi or hair-like pro-
jections are also found in great abundance upon this mem-

FiG. 116.

A Portion of the Ilium highly magnified, show
ing Peyer's Patches and the Villi.

A Portion of one of Brunner's Glands. A Vievr of a Longitudinal Section of the

Jejunum, showing the Villi as seen under
the Microscope. 1, 1, The Terminal Orifices of the Villi. 2, 2, The
Internal Coats of the Intestine. 8, The Peritoneal Coat.

How 13 the Mncoiu membrane arranged through the canal, and what is the design of
6uch an arrangement?

AXD PHYSIOLOGY. 1&5

brane, in order to increase the amount of its secretory surface.
It is the presence of villi that gives to some parts of the mu-
cous membrane a velvet-like appearance, and in these villi
are found the commencement of the lacteals, one lacteal
usually being found in each villus.

303. Glands attached to tlie Intestines. — Connected
with the Alimentary Canal are several large glands, a few of
which have already been described. They are soft solids, of
various forms and sizes, and are composed of lobules or small
divisions, each one of which is supplied with an artery, vein,
and duct. Each of these ducts communicates with the prin-
cipal duct or outlet, which conveys away the product sepa-
rated from the blood by the whole gland. In microscopic
structure, a gland is made up of very minute cells, which
seem to have the power of secreting or separating from the
blood the particular substance which it is the function of the
gland to eliminate.

304. Tlie Liver, Gail-Bladder.— First in importance of
this class is the Liver. (Fig. 178, p. 166.) This, except-
ing the brain, is the largest organ in the body, and is situated
on the right side of the abdomen, corresponding to the stom-
ach on the left, and is of a reddish yellow color. The average
weight of it is four pounds, measuring twelve inches in its
longest diameter, and it is divided into five lobes or great divis-
ions, and these are entirely composed of minute bodies or
lobules, (Fig. 179, p. 166), w^hich are about the size of millet
seeds, each one containing an artery, a vein, and a plexus, or
net- work of ducts for conveying away the bile. These differ-
ent plexuses unite with each other and form two hepatic ducta
which discharge the bile into the Gall Cyst or bladder. (Fig.
180, p. 167.) This is a pear-shaped sac, containing from
one to two ounces, of a greenish yellow color, situated under

Describe the Villi. 303. What is said of the larsre glands connected wi'h the organs of
digestion? State the structure of a gland. 304. What is the relative size of the Liver?
Where is it located? State its color and weight. Give its minute structure. What is
the Gall Cyst or Bladder? What is the duct that carries the Bile to the Gall Cyst, nnd
the one that empties the Gall Cyst into the Duodenum ?

166

HITCHCOCK'S ANATOMY

Fig. 178.

The Inferior or Concare Surface of the Liver, showing its Subdivisions into Lobes.

I, Center of the Eight Lobe. 2, Center of the Left Lobe. 3, Its Anterior, Inferior, or
Thin Margin. 4, Its Posterior, Thiclc or Diaphragmatic Portion. 5, The Eight Extrem-
ity. 6, The Left Extremity. 7, The Notch on the Anterior Margin. 8, The Umbilical
or Longitudinal Fissure. 9, The Pound Ligament or remains of the Umbilical Vein.
10, The Portion of the Suspensory Ligament in connection with the Pound Ligament.

II, Pons Ilepatis, or Band of Liver across the Umbilical Fissure. 12, Posterior End of
Longitudinal Fissure. 13, 14, Attachment of the Obliterated Ductus Yenosus to the
Ascending Vena Cava. 15, Transverse Fissure. IG, Section of the Hepatic Duct. 17,
Hepatic Artery. IS, Its Eranches. 19, Yena Portarum. 20, Its Sinus, or Division into
Eight and Left Branches. 21, Fibrous remains of the Ductus Yenosus. 22, Gall-Blad-
der. 23, Its Neck. 24, Lobulus Quartus. 25, Lobulus Spigelii. 26, Lobulus Caudatus.
27, Inferior Vena Cava. 28, Curvature of Liver to fit the Ascending Colon. 29, De-
pression to fit the Eight Kidney. 30, Upper portion of its Eight Concave Surface over
the Eenal Capsule. 81, Portion of Liver uncovered by the Peritoneum. 82, Inferior
Edge of the Coronary Ligament in the Liver, 3), Depression made by the Vertebral
Colmnn.

Fig. 179. the right side of the

liver, and has a
small vessel called
the Bile Duct, which
enters the Duode-
num obliquely about
three inches from
the stomach.

305. Pancreas.—
The Pancreas ("all
flesh," because there
is no fat ever found

Transverse Section of a Lobul« of the Human Liver. ^ 1"^) 13 another

and physiology,

Fig 180.

167

A View of the Gall-BIadder dlstendecl with Air, and with its Vessels Injected.
1, Cystic Artery. 2, The Branches of it which supply the Peritoneal Coat of the
Liver. 8, The Branch of the Hepatic Artery which goes to the Gali-Bladder. 4,
The Lymphatics of the Gall-Bladder.

gland, lying directly behind the stomach. It is about six
inches in length, the right end of it being somewhat larger
than the left extremity, and hence called the head. To the
naked eye the lobular structure is apparent : but each lobule
is itself made up of much smaller lobules. The duct of the
Pancreas conveys the milk-like secretion of this gland, to
nearly the same point on the Duodenum as the Hepatic Duct,
where they both enter that tube in a slanting manner, so that
by the valvular arrangement the contents of the intestine can
not be forced backwards into the Biliary or Pancreatic duct.

Fig. 181.

An Anterior View of the Pancreas, Spleen and Duodenum, with their Blood-Ves-
sels Injected. 1, The Spleen. 2, Its Diaphragmatic Extremity, 3, Its Inferior
Portion. 4, The Fissure for its Vessels. 5, The Pancreas. 6, Its Head, or the
Lesser Pancreas. 7, Duodenum. 8, Coronary Arteries of the Stomach. 9, The
Hepatic Artery. 10, The Splenic Artery. 11, The Splenic Vein.

805. Describe the Pancreas. What is its structure ? Where does its duct empty, and
what mechanical structure in it makes it remarkable ?

m

HITCHCOCK'S ANATOMY

Fig. 182. 306. Peritoneiim.—

The Peritoneum, ''cov-
ering about," or exter-
nal coat of the intes-
tines is not a little pe-
culiar in its conforma-
tion. This, like all
serous membranes, first
completely invests the
organs and then is re-
flected from them so as
to make a lining for the
whole cavity. Hence
the cavity of the ab-
domen, although a per-
fectly shut sac, is of
very irregular outline.
That it is a shut sac
may be seen from the
fact that in dropsy of
the abdomen — the fluid
has no means of escape
except by absorption, or
puncture from the out-
side. In the disease
commonly known as in-
flammation of the bow-
els, this membrane u the principal seat of the difiiculty, and
the inflammation of this as well as of all other serous mem-
branes, is attended with acnte pain, and the progress of the
disease, for better or v/orse, very rapid.

S07. The Mesentery and tne Omentum. — These are folds
of the Peritoneum, attached to diflerent parts of the abdomen
and its viscera, \vhich serve to retain some of the organs in

Eeflexions of the rcritoneum. J). Diapliragra.
S. Stomach, C. Colon. I>. Duodenum. I\ Pan-
creas. /. Small Intestine. Ji. Eectum. B. Blad-
der. The numbers indicate t'.ie course of the
Peritoneum.

S03. What is the Peritoneum ? Is the cavity of the abdomen of a regular outline?
What is the principal seat of disease i:i inflammation of the bowels? 307. "^Vhat is the
Mesentery and the Omentum ? Wh it is it thickly packed with?

AND PHYSIOLOGY.

1G9

their positions, and also, from tli3 amount of fat contained in
them, to protect the intestines from cold and mechanical
violence, and to furnish a soft surface for them to glide over
in their various movements. In a lateral view of the abdo-
men, Fig. 182, some of the parts of the Omentum and Me-
sentery may be seen. At 4 is seen what is known as the
lesser Omentum, connecting the Liver and the Stomach. At
5 and 6 are seen the folds which constitute the greater
Omentum. At 10 is found the Mesentery, which encircles
the small intestines. This is a broad fold of the Peritoneum
connected to the middle of the cylinder of the Jejunum and
Ileum throucjh their whole lenojth, and is attached to the
posterior wall of the abdomen. Within the layers of the Me-
sentery are found from 130 to 150 bodies of almond shape
and size, known as the Mesenteric Glands. Through these
the Lacteals pass on their way to form the Thoracic Duct.

808. Lacteals. — The Lacteals are minute vessels, which
commence with the inner or mucous coat of the intestines,
Fig. 183.

Aorta. Thoracic Canal. Lymphatic Glands.

( Eadicles of the
■< Chyliferoua
( Vessels.

Intestine.

Lacteals. Mesenter)-.

Chyliferous Vessels.

What small bodies are found in It, and what is the use of the Mesentery!

176

HITCHCOCK'S ANATOilY

Fig. 184.

and terminate in the Tlioracic
Duct. These at their com-
mencement are about the
same in anatomj with the
radicles or small veins, and
at this point act the part of
absorbents. Soon after they
have left the Intestines, sev-
eral of them unite into one
and pass through small bodies
of about the size of peas,
called the Mesenteric Glands.
As they emerge from these
glands, they are fewer in
number but larger in size,
until they all unite into one
tube called the Thoracic Duct,
a little larger than a goose
quill, at about the point of
the last Dorsal Vertebra.
This vessel passes immedi-
ately upwards, lying closely
upon the Spinal Column,
sometimes separating into two
smaller tubes for a few inches.

A View of the Course and Termination of the Thoracic Duct. 1, Arch of the Aorta.
2, Thoracic Aorta. 3, Abdominal Aorta. 4, Arteria Innominata. 5, Left Carotid. 6,
Left Sub-CIavian. 7, Superior Cava. 8, The two Venae Innominatse. 9, The Internal
Jugular and Sub-Clavian Vein at each side. 10, The Vena Azygos. 11, The Termina-
tion of the Vena Hemi-Azygos in the Vena Azygos. 12, The Receptaculum Chyli : sev-
eral Lymphatic Trunks are seen opening into it. 13, The Thoracic Duct dividing, op-
posite the Middle Dorsal Vertebra, into two branches, which soon re-unite; the course
of the Duct behind the Arch of the Aorta and Left Sub-Clavian Aorta is shown by a
Dotted Line. 14, The Duct making its turn at the Root of the Neck and receiving sev-
eral Lymphatic Trunks previous to terminating in the Posterior Angle of the Junction
of the Internal Jugular and Sub-Clavlan Veins. 15, The Termination of the Trunk of
the Lymphatics of the Upper E-Ktreniity.

308. Where do the Lacteals begin, and where do they terminate ? What do they re-
semble, and what do they pass through ? State the size of the Thoracic Duct, its course
and termination.

AND PHYSIOLOGY

171

until it reaches a point as high as the clavicle, where it
gradually curves forward, and joins itself to the left sub-
clavian vein. The Lacteals and Thoracic Duct are all made
up of three coats and present a silvery white appearance
from the color of the fluid they contain. Their function is
to convey the Chyle or nutrient portion of the food into the
blood.

309. Ridiieys. — The Kidneys are two in number, situated
upon the side of the lumbar vertebrae, and are generally en-
closed in a large amount of fat. Their average size is be-
tween four and five inches in length, two and a half inches in
breadth, and one in thickness. Their color is of a reddish
yellow, and form decidedly oval, with a depression in one of
the sides. Upon its upper extremity is a small body, called
the Renal Capsule, and the whole organ is abundantly sup-
plied with blood. The design of it seems to be the removal

Fig. 185.

Fig. 186.

Diagram of the Urinary Apparatus, a^,
The Kidneys. 1>, The Ureter, c, The
Bladder, d, Canal of the Urethra.

A Section of the Eight Kidney surmounted by the Eenal Capsule. 1, Supra-Renal
Capsule. 2, Cortical Portion. 3, Medullary or Tubular. 4, Two of the Calices
receiving the Apex of their corresponding Cones. 5, The Infandibula. 6, The
Pelvis. 7, The Ureter.

"What vein does it empty into ? What fluid does it carry ?
features of the Kidneys. What is found upon its upper edge ?

State the leading

172 -HITCHCOCK'S ANATOMY

of the waste Nitrogen of the system, and many salts, espe-
cially the Phosphates, which can be eliminated by no other
organ. The secretion of the kidneys is the urine, upon
the regular secretion of which the health of the system greatly
depends.

FUNCTIONS OF THE DIGESTIVE ORGANS.

310. Mastication; Use of the Tongue; Use of the Saliva.
Amount of Saliva. — The first process through which the food
must pass is Mastication, or reducing it to a pulp by means of
the teeth and admixture of the saliva. The service of the tongue
is to keep the food between the teeth and to place it in such a
position that it will readily receive the saliva. The saliva is
of use to moisten the food, since the gastric fluid will much
more readily dissolve it than if dry or solid. It aids articu-
lation and the sense of taste by keeping the lining of the
mouth in a moist and pliant state. It also is of use to cleanse
the mucous membrane, and by its moisture to quench or pre-
vent thirst. Air is also carried by it into the stomach to aid
the process of digestion. But the most important use of this
fluid is the conversion of starch into sugar. This property
depends mainly upon a peculiar organic active substance con-
tained in it called Ptyalin, and is most active when in a state
of incipient decomposition. The saliva secreted daily varies,
according to diiSerent authorities, from about three pounds to
six pounds and a half, and is alkaline in its character. Acid,
aromatic, and pungent substances increase the amount of the
secretion very much.

311. Deglutition. A part of the Process involuntary.
— After mastication, the next process is that of swallow-
ing, or deglutition. The first step is to place the bolus,
or mouthful, upon the back part of the tongue, when by

Ofwhattcroat use are the Kidneys? 310. Describe the process of Mastication. Of
what use is the Saliva ? How much is secreted every day ? What increases its amount?
311. Describe the process of swallowing.

AND PHYSIOLOGY. 1 7.3

the muscles of the tongue and fauces it is forced into the
Pharynx. As soon as it fairly enters this passage, the mus-
cles by an involuntary movement seize it, and force it rap-
idly past the opening into the lungs, and at the same
moment the epiglottis is forced down upon the larynx, to
prevent its entrance into the trachea. This part of the pro-
cess is involuntary, from the necessity of keeping the passage
to the lungs open as much as possible, in order to admit air,
and also from the great danger of introducing any other sub-
stance. And so perfectly carried on is this function that it is
seldom — compared with the frequency of deglutition — that
even a fluid escapes the vigilance of this sentinel.

312. Passage of the Food through the Esophagus. — The
food passes slowly through the Esophagus into the stomach,
it being forced along by the contraction of the muscular
fibers, aided by the oily secretion of the JEsophageal glands.

813. Gastric Digestion. — As soon as the food reaches the
stomach, the most important part of the process of digestion
commences, all the previous steps being preliminary. When-
ever any solid substance comes in contact with the inner or
mucous membrane of the stomach, it excites the gastric glands
to pour out in abundant quantity the Gastric fluid.

314. Gastric Fluid— its Amount— Pepsin. — This fluid is
a transparent liquid of a little greater consistency than water,
and of a perceptibly acid taste. It possesses the property of
coagulating albumen, and of separating the whey or serum
from the milk in a very short time, and is secreted at the rate
of seventy ounces per day. This property, however, is owing
to a peculiar organic compound called Pepsin, which acts after
the manner of a ferment at the normal temperature of the
human body. The Gastric fluid also possesses antiseptic

What part of the process is under, and what part is not under the control of the will?
812. How is the food carried through the Esophagus? S13. Where does the inost im-
portant part of digestion take place? What effect has any solid substance upon the Gas-
tric Glands of the Stomach ? 314. What are the properties of the Gastric Fluid? How
much is secreted daily ? What effect has it on the decay of substances ?

174 HITCHCOCK'S anatomy

properties, or the power of preventing decay or putrefaction
for a long time. These three properties, the acid, fermenta-
tive, and antiseptic, are of service in the following manner.
The acid assists in the solution of the different materials in
the stomach. The Pepsin, which constitutes two thirds of
the solid materials of the gastric juice, does its office bj es-
tablishing the lactic fermentation, such as is seen in the
changes through which milk passes in hot weather. The
antiseptic properties are important in order to prevent putre-
faction, which would be so liable to be set up among organic
substances in such a condition, and at such an elevated tem-
perature as the stomach usually possesses.

315. Digestion partly dependent on Chemical Action.—
Thus we see that this part of digestion is mainly a chemical
affair, although not entirely so : since by experiments care-
fully conducted in a vial outside of the body, maintaining the
same temperature and all the essential conditions of digestion,
the process goes on very slowly and quite imperfectly. It
was found, however, that a piece of meat did digest in a vial
in nine hours and a half, while that in the stomach under
precisely similar circumstances, was digested in one hour and
a half

316. Digestion partly a vital Process. — Consequently to
say exactly what stomach digestion is, must at present be im-
possible. We can only say that it is a chemico-vital process,
essentially a chemical action depending upon vital power.

317. Movements of the Stomach in Digestion. -In order
to bring the food in contact with the largest amount of Gastric
Fluid, the stomach, by an instinctive movement, carries its
contents over the greater curve in it, frcm the right to the
left, and returns it in a reverse direction, occupying about

What constituent is it that is primarily essential in this process? 315. How much of
the process thus far flescribecl is mainly a chemical one ? What experiment proves it ?
S16. What definition can be given of Digestion ? 317. What instinctive movements doeg
the stomach seem to possess?

AND PHYSIOLOGY. l7o

three minutes for each revolution. And in order that all of
it may be permeated bj this fluid, contractions frequently
take place in the muscular coat of the stomach, resembling a
churning process.

318. Intestinal Digestion, Chyme. — The process thus
far is Gastric Digestion, or that which takes place in the
stomach, and the object accomplished seems to be the con-
version of the nitrogenous constituents of the food into albu-
minose called histogenetic digestion, or the preparation of the
food to be made into the tissues of the body. But when all
the food is thoroughly dissolved, or made into a liquid condi-
tion called Chyme, the Pyloric orifice is opened, and the food
passes into the Duodenum. When it arrives here — and never
sooner, in a healthy state — the secretions of the Liver, Pan-
creas, and mucus of the Intestine mix with it, performing the
second or Intestinal digestion, which is called calorifacient or
heat making, since it prepares the food which supports the heat
of the body. The process, however, is somewhat obscure, aU
though it is certain that food is not perfectly fitted for absorp-
tion until it has well completed this process.

319. Use of the Pancreatic Fluid. — ^The Pancreatic Pluid
secreted at the rate of from five to seven ounces per day, re-
sembles quite closely the Saliva, converting starch into sugar,
and aiding in the absorption cf fatty matters, by forming an
emulsion, which, however, is much more readily formed by
the presence of bile.

320. Action of the Bile, an Antacid and Excre-
tory Agent. — The Bile, thrown out at the rate of fifty-four
ounces a day, seems from its large quantity to be of no
little importance. And since the juices of the stomach are
mostly acid in their character, it seems desirable that there
should be some counteracting agent, which is furnished in the

818. What 13 the principal thing accomplished by stomach digestion ? What is food
called after it has passed through this process? Describe Intestinal digestion and Its
use, 819. What amount of Pancreatic fluid is secreted daily ? What is its principal use ?
820. How much Bile is secreted daily?

8*

1 76 ir I T c II c o c K ' s anatomy

highly alkaline character of the biliary secretion. Another
use of the bile is to remove certain materials from the blood
(the carbonaceous), by allowing them to pass oflf with the
waste portions of the food, the liver thus performing the office
of an excretory organ. The liver also seems to possess the
power of forming sugar and even fat, when it is not contained
in the food, thus seeming to act the part of an equilibrator in
the process of blood making. And since all the blood re-
turning from the small intestines passes through the liver
before going to the heart, without doubt an important change
is accomplished in it by the liver, although the change is as
yet by no means fully understood.

321. Purposes for which Food is required. Two kinds
of Materials in the Food, azotised and non-azotised.
Azotised Constituents. Albumen, Fibrine, Casein, Gela-
tin.— In the animal body we find that food is required for at
least three purposes : First, to build up the organism at the
outset, or, in other words, to secure its first growth. Second,
to maintain the organism at its normal standard after its
growth is complete, or to furnish material to supply the waste
which is perpetually going on while life lasts. Third, to
maintain the proper temperature of the system. Hence there
must be at least two kinds of material contained in the food:
one that will sustain and promote the growth of the tissues
called histogenetic, and another that will keep up the heat of
the body to a proper standard, called calorifacient. The first
of these requisites is found in food containing Nitrogen, called
azotised, and the other in that with no Nitrogen, called non-
azotised. Of the azotised food the most important constituents
are Albumen, Fibrine, Casein, and Gelatin. Albumen is fami-
liarly known as the transparent portion of an egg before it is
cooked, or the white of the egg after a cooking process. It ex-
ists also in the blood, muscles, and bones of all animals, and is

How is its alkaline character serviceable ? Wliat other processes does it accomplish ?.
821. What three purposes is food required for ? Hence what two kinds of food must ba
brought into the system ? Give examples of azotised food.

A N D P II Y S I O L O G Y . 1 77

coagulated or made hard and white by heat or mixture with
Nitric Acid. In some parts of vegetables also, especially in
the seeds and fruit, is found a substance which, from its re-
semblance to animal albumen, is called vegetable albumen.
Fibrine exists in the blood and muscles of animals, forming
the coagulum or clot of blood, and the proper muscular sub-
stance. There is also a corresponding substance in plants
known as vegetable Fibrine. Casein closely resembles Albu-
men in its constitution, but differs in many of its physical
properties. For while Albumen is coagulated by heat, Casein
is only coagulated by lactic and acetic acids. Casein is best
seen in cheese. These three substances are the essential ele-
ments of nutrition in mammals, and though every other prin-
ciple may be supplied in the food, yet the body is insuflBciently
nourished without Albumen and Fibrine. Gelatin, which
exists abundantly in the cartilage of animals, is another
azotised principle of food. This, however, of itself can not
support life, although it can be changed into albumen, or
some of its compounds by the action of the fluids of the
stomach.

322. Non-azolised Constituents.— Of the non-azotised
constituents of food, the Saccharine and Farinaceous and
Oily, are the principal ones, although there are many others
of less importance. Of the former, the principal element is
starch, while the sugar is secondary or subsidiary to it, and
in the latter we find an abundance of a Hydro- Carbon, or a
compound of Hydrogen, Carbon, and Oxygen, and all are
essential elements in combustion.

323. Is an exclusively Animal or Vegetable Diet tiio
best adapted to Man? Testimony of Experience. Ex-
perience of Dr. Kane.— The question then which naturally
suggests itself here is, whether man is adapted to live ex-

What eflfect has heat and Nitric Acitl upon Albumen ? Where is Fibrine found ? How
does Casein differ from Albumen? Will Gelatin (or Jelly) of itself support life ? 822.
What are examples of non-azotised kinds of food ?. 323. Is man made .to live on an ex-
clusively vegetable or animal diet ?

178 HITCHCOCK'S ANATOMY

clusively upon vegetable or animal diet. An answer cornea
to us from both experience and chemistry. For while on the
one hand hundreds of examples are adduced, as showing that
some men have lived to a green old age in solid health, who
have entirely refrained from animal diet, and many others
who probably would have shortened their lives a score of
years by the use of animal food, have prolonged it by adopt-
ing a vegetable regimen, an equal number of cases can be
mentioned to show that a mixed diet has promoted equally
long and healthy lives. The geographical distribution of man,
as well as the manner of life, also furnishes valuable evidence
in this case. Travelers who have visited the polar regions, and
pre-eminently Dr. Kane, give us undoubted testimony of the
necessity of eating meat and animal fat to keep the body in
health : since the low temperature not only requires a greater
amount of combustive material, but this greater energy of
respiration produces a more rapid waste of all the tissues of
the body, requiring a more abundant supply of azotised and
non-azotised material to supply the deficiency. And on the
other hand experience shows^ that in tropical climates stimu-
lating food and drink should be avoided, because the high
temperature of the atmosphere depresses vital energy, and
consequently less material for supporting animal heat is re-
quired with a corresponding decrease in the waste of the
body.

324. Example of the Esquimaux. — As examples of these
principles one traveler among the Esquimaux relates that these
people relish very heartily tallow candles as a dessert for din-
ner. Another states that he has seen the Greenlanders eat
from twenty to thirty pounds of blubber, or whale -fat, at one
meal. This, however, was a sufiiciency of food to them for
two or three days.

Give the testimony of experience. Give the argninent derived from difference in
climate. What kind of food is necessary to support life in polar, and what intropicaj
countries? 324. State luxurious articles of diet among Esquimaux and Greenlanders.
How much will a Greenlander sometimes eat ?

AND PHYSIOLOGY. 179

825. Voice of Chemistry.— Chemistry, however, teaches
us that we can find in the vegetable world all the principles
necessary to support the body without using animal food.
And although the vegetable kingdom contains those elements
which will support life in many instances, yet we know,
as a general rule, that we find man in the highest degree
of bodily and mental vigor, only when he makes use of
a mixed diet. And we also find that all animals which are
the most active in their habits, and rapid in their motions, are
feeders upon animal flesh. There is also a race of half civil-
ized savages, the Guanchos, who spend the greater part of
their lives in the saddle and constantly in a state of great
activity, who live almost exclusively upon animal diet, and
yet are unequaled in their powers of physical endurance, and
live lives fully equal to the average in duration.

326. Argument from the Teeth. — The strongest physio-
logical argument in favor of a mixed diet, is found in the
conformation of the teeth and alimentary canal of man. In
those animals which live exclusively upon animal diet, the
teeth are sharp and pointed, with a very short alimentary
tube, since the nutrient portion of the food is readily absorbed
by the lacteals. On the other hand, the teeth of vegetable
feeding animals are smoothed upon their upper surfaces, being
adapted to crush vegetable substances, and the alimentary
tube very long, since the nutrient portion of vegetable food is
not so readily parted with. Now in man we find neither of
these apparatuses perfectly complete, but an admixture of
both. Part of the human teeth are of the carnivorous or
flesh eating kind, and another part of the herbivorous or
vegetable eating kind : but each of them so modified, that
either kind of food can be readily prepared for digestion.
The alimentary canal too is intermediate between that of the
carnivorous and herbivorous type, being equally well adapted

325. What does chemistry teach on this subject? How does great bodily activity
affect the diet as illustrated by the Guanchos ? 326. State the argument derived from
the te«th. What two kinds of teeth are found in man ?

180 HITCHCOCK'S ANATOMY

to the digestion of animal or vegetable food, or an admixture
of both.

327. Conclusions. — The kind of food which is the most
perfectly adapted to the constitution of man, seems to be de-
termined hy the following rules, based upon the temperature
of the climate, the habits or employments of life, and the
health of the individual.

First. The lower the temperature the greater the amount
of animal heat necessary for the support of life, which re-
quires the fattest portions of the meat.

Second. The more active the habits of the individual, and
the greater the amount of exposure in the open air, the greater
the demand for animal food.

Third. If the system be suffering under inflammation of
any sort, or if there be any tendency to inflammation, animal
food should be used very sparingly, or entirely dispensed
with.

Fourth. That diet seems to be the most perfectly adapted
to the human constitution in all climates and seasons, which
is composed of animal and vegetable food in the proportion of
one to two, or one third by weight of animal food to two
thirds of vegetable food. This proportion is the basis of the
diet scales of the United States and British Navies.

328. Use of the Lacteal s. — The use of the Lacteals is to
absorb the Chyle or nutrient material from the contents of the
intestines, and .carry it into the general circulation. The
force by which this fluid is taken from the alimentary canal,
is by no means understood at present, unless it be capillary
ittraction.

329. The Chyle.— The Chyle is a white liquid somewhat
thicker than milk, and is made up of a solution of albumen
containing minute globules, or cells, which are mostly spher-

■ ^'7. What fonrconcln&ioiis arc drawn from this wHolc snlject of diet? 828. What is
tb*- function of the Lacteals? What is the- force that circulates the Chyle? S29. Do..
iicri«>o the Chyle.

AND PHYSIOLOGY

181

ical and about 3-o^ooth of an inch thick, and Chyle Cor-
puscles, -which are simple cells about jo^o-oth of an inch in'
diameter.

330. The Place where the Chyle enters the Blood. —
Principle of Venturi. — As already mentioned the Chyle en-
ters the blood through the left Subclavian vein of the neck.
It is not, however, simply by the opening of one vessel into
another that this is accomplished, but advantage is taken of
the union of two currents, so that by their combined force
the chyle is drawn in towards the heart. The mouth of the

Pig. 187.

Position of the Thoracic Duct and tho Veins of the Neck where it empties.
S. V. Subclavian Vein. J. Jugular Vein. J). Thoracic Duct.

Thoracic Duct, however, is provided with valves to prevent
the blood from entering it, in case obstruction in the veins
should occur. And " it is a physical fact that, when a small
tube is inserted perpendicularly into the lower side of a hori-
zontal conical pipe, in which water is flowing from the nar^

Give the size of the Chyle Corpuscles. 330. Give the description of the hydraiili«
principle hy which tho chyle is drawn towards the heart

182

HITCHCOCK'S ANATOMY

Fig. 188.

Illustration of the Principle of Yen-
turi. "When a current passes tlirough a
large tube, if another smaller tube open
into its side, the current in this tube
will be drawn into the large tube, even
against the force of gravity.

rower to the wider portion,
if the vertical tube be made
to dip into a vessel of water,
not only will the water of the
larger pipe not descend into
the vessel, but it will draw
up the water through the
small tube so as to empty
the vessel." This is called
"the principle of Yenturi,"
and is well illustrated by the
entrance of the Thoracic Duct
into the Subclavian vein, as
seen in the cut No. 187. A
diagram illustrating the same
principle is seen in Fig. 188,
the arrows representing the
direction of the currents, and
the smaller, perpendicular
tube illustrating the Thoracic
duct at its entrance between
the veins of the neck.

331. The Lymphatics. — The Lymphatics in general
structure and function resemble the lacteals. The lacteals,
however, are designed exclusively for promoting the growth
of the tody by adding nutrient materials, while the lympha-
tics give up to the general circulation not only useful pro-
ducts, but all those which are absorbed. Hence whatever is
presented to the mouths of the lymphatics, is carried into the
general system, while injurious products are not usually taken
up by the lacteals. (See also page 284.)

332. The Action effected by the Lymphatics. — Since
the Lymphatics, as already described, are found in every

Illustrate the principle of Venturi. 331. Give the general structure of the Lyaiphac
tic*. State the probable differences in function between these and the Lacteals.

AND PHYSIOLOGY. 183

part of the body in great numbers, and are almost constantly
at work in removing the waste particles, it follows that in
process of time a large part, or even the whole of the body,
will be removed. And it is generally admitted that the
whole body is actually renewed every few years, although
the precise number can not be stated, since so many circum-
stances modify the change, such as exercise, the amount of
food taken, and climate, as well as other causes not so easily
understood. It is, however, quite probable that the period
of ten years is sufficient to complete the change in most in-
dividuals, and the number is stated by some as low as seven.

HYGIENIC INFERENCES.

833. 1. From the structure and functions of the Digestive
Organs we can derive some hints as to the manner of pre-
venting acute and chronic diseases in them.

334. Danger of Eating too much.— 2. We see that there
is a great danger of eating too much. Large quantities of
food distend the coats of the stomach, and give too much labor
for them to perform. As a natural consequence the gastric
glands are weakened from excessive action, and then indiges-
tion or some other diseased action is sure to follow. And in
how much better health would multitudes in the higher classes
of society be kept, if some of the numerous dishes they use
were omitted! And in this country the remark applies to
nearly all classes.

335. We are apt to eat too many Kinds of Food. — 3. We
also see that our meals are generally m^ade up of too many
kinds of food. In the habits of the lower animals we dis-
cover a great simplicity of diet. Even in those whose ana-
tomical structure closely resembles that of man, the appetites

332. How great changes are effected in the body by the Lymphatics ? In what length
of time is the body probably entirely renewed? 334.. What is the injury from eating
too much ? 335. What is said about eating too many kinds of food ?

184 HITCHCOCK'S ANATOMY

are easily satisfied bj the simplest food. Nor does man's
intellectual superiority demand a greater variety in diet, all
that is requisite being the materials necessary to support the
growth of the different tissues.

335a. 4. It is evident that condiments and spices should
be always used very sparingly^ and generally spices not at
all. To be sure nature seems to indicate the want of a mode-
rate supply of salt (perhaps for the juices of the stomach),
but pepper, mustard, and ketchup excite the coats of the
stomach to an action that is unnatural. And it seems to be
a law of the system that stimulants and opiates, if used
regularly, must be constantly increased in quantity, other-
wise they will lose their effect, and disorder will follow. In
fine, all experience seems to prove that the demands of nature
for food are very simple and easily gratified ; but the appetite
may be so trained as to loathe every thing of a simple and
natural kind, and be satisfied only with the stimulating com-
pounds of modern cookery. The law of nature, however,
cannot be reversed, that he who lives in the simplest manner
lives the longest, and sufiers the least from pain or disease.

336. lYc must not eat too fast. — 5. Most persons eat too
fast. No time is gained on the sum total of life, by taking
any from that demanded by nature for eating and digesting
food. A fortune or great reputation, it is true, may some-
times be gained a little quicker by using the time which the
stomach rightfully claims, yet the penalty for such robbery is
a shorter life, or a disease which makes life miserable.

337. The Time of Eating.— 6. We see that the time of
eating shoidd not encroach upo7i the hours devoted to sleepy
or those of hard labor. During sleep the brain needs quiet;
but if there be any function going on such as that in the
earlier stages of digestion, the brain, as a matter of necessity,

Does intellectual superiority require so great a variety as is often introduced ? 835.
Why arc condiments and spices to be used very sparingly? What are the demands of
nature upon the appetite? How much may the appetite be perverted? 836. What
danger in eating too fast ? 337. What time during the day should we eat?

AND PHYSIOLOGY. 185

must labor till the process is accomplished, and as a result,
dreams or imperfect trains of thought will produce that kind
of sleep which cannot refresh the body. If again the time
for meals precede or follow very closely upon hard labor, a
law of nature is broken, and the penalty is sure to follow.
The nervous energy cannot be immediately called off from
the part to which it has for some time been directed (whether
to the brain or the muscles), and consequently the stomach
for a while must lie nearly inactive. Hence a short season
of relaxation from all active exercise, whether mental or
physical, just before and after meals, is very conducive to
health, since in the former case the circulation is equalized,
and the brain can prepare its energies to expend them on the
stomach, while after meals the whole force of the nervous in-
fluence is needed for a time by the digestive function before it
can be directed to the muscles for exercise. Even a short
time after dinner devoted to a nap promotes digestion quite
rapidly, although the habit often is an inconvenient one, to
say the least, since if by unavoidable circumstailces it is omit-
ted for once, the person feels uncomfortable the rest of the
day.

338. Danger of employing Stimulants for weak Stom-
achs.— 7. We see the error and danger of a- very common
practice : that when the digestive organs become iceak, and
the appetite is poor^ stimulants are employed to waken the
stomach to crave more food than it can digest. This only
aggravates the difficulty and makes a demand for stronger
stimulants, and thus often is the system prematurely worn
out. Whereas, would men follow nature and when a dimin-
ished appetite teaches them to eat less and give the organs an
opportunity to rest, they would ere long rally and digest all
that is necessary to give tone and energy to the system. To

Why should not hard labor and a full meal come closely together ? How does a short
nap after dinner affect digestion ? What is a serious objection to the habit? 38S. What
danger results from using stimulants to help weak stomachs ? Should we eat more than
the natural appetite craves ?

186

HITCHCOCK'S ANATOMY

eat more than the stomach craves, is not the way to gain
strength, but to increase weakness and shorten life.

COMPARATIVE SPLANCHNOLOGY.

339. Digestive Organs of Mammals. — In many mam-
mals the digestive organs in their general arrangement and
construction resemble those of man.

Fig. 189.

Maxillary Gland.
Trachea.

Parotid Gland.

Pharynx.
^Gullet.

Colon.

Caecum.

Bmall Intestine.

Stomach.
Pancreas.

Siileen.

Kidneys.

Colon.

Abdomen.

Eectum.

Bladder.

Digestive Apparatus of an Ape.

340. Esophagus of the Horse. — In the Horse, however,
at the lower end of the Esophagus, there is a sickle-shaped

340. How does the Esophagus of the Horse differ from that of a man ?

AND PHYSIOLOGY.

187

fold of lining membrane, which makes it impossible for this
animal to vomit.

841. Stomach of Ruminants. — Mammals, as a general
rule, have very simple stomachs, and particularly those
which live upon animal food. But in those herbivorous
ones which chew the cud, this organ consists of four cavities,

Fia. 190.

Duodenam.

Pylorus. The Eennet. 2d Stomach. Paunch.
Stomach of the Sheep.

the Ingluvies or "Paunch," the Reticulum or ''Honey
Comb," the Omasum or "Many Plies," and the Abomasum

Pig. 191.

Gullet.
Esophageal Groove. _^

Maniplies, or Third
Stomach.

Eennet, or Fourth

Stomach, — "

Duodenum.

'^'M^i^^^^^^^^is,

pylorus. Second Stomach. Paunch.

Interior of Stomach of the Sheep.

841. What is the number of stomachs in herbivorous animals ? Give the names ci
esush.

188

HITCHCOCK'S ANATOMY

Pig. 192.

or «Ked." As the
food enters the Inglu-
vies, it is simply mixed
with the fluid secreted
by its coats, when it
passes into the Reticu-
lum, where it not only
receives additional se-
cretions, but is made
into little ''cuds" or
"pellets," which, when
the animal is at rest,
are returned to the
mouth for the purpose
of re-chewing and mix-
ing with the saliva.
After this process is
completed, they are sent into the Omasum, which cavity
seems designed to prepare the food to enter the fourth stom-
ach where the true process of digestion takes place. And
it is from this fourth stomach or Abomasum, that the Rennet
is taken from young calves, and used by cheesemakers for the
purpose of coagulating the milk.

342. Reason of this Complex Stomach. — The probable
reason of such a complicated stomach in these animals is that
since they have such poor means of self-defense, they need to
crop their food as quickly as possible, and then retire to a
safe place to masticate it. And it is also partly owing to the
fact that vegetable substances require a longer process for di-
gestion than does animal food.

343. Lpn<?th of Intestine.— The length of the Intestine
depends as a general rule upon the food used by the animal,

Stoinacli of the Ox. A. Paunch. B. Ke-
ticuluin. C. Omasum. D. Abomasum.
-E*. Pylorus. K Duodenum. G. Esopha-
gus.

Give the process of chewing the cud in these animals. 842. What is one important
reason for this complicated arrangement? 843. Upon what does the length of Intestine
depend?

AND PHYSIOLOGY. 159

the vegetable feeders having a long tube, and the flesh feeders
a short one, since animal food is so easy of stomach digestion,
and the nutrient portion of it so readily taken up by the
lacteals. Thus the ox has an alimentary tube fifteen or
twenty times the length of the body, amounting in a full
grown animal to 150 feet, the sheep one twenty-eight times its
length, while many of the carnivora exhibit one only about
three times the length of the body. The true Cetacea or Whale
tribe are the only ones w^hich do not have a marked distinc-
tion between the large and small intestine.

344. The liver. — The Liver as in man is one of the
largest organs in the body, and is much more divided into
lobes in carnivorous than herbivorous animals. It is smallest
and least divided in those animals with compound or rumi-
nating stomachs.

345. Bill of Birds. — Birds are destitute of teeth, since
the process of mastication is carried on in a certain portion
of the alimentary canal. But the horny investment of the
jaws known as the bill, is harder in birds of prey, and those

Tig. 193.

Os Hyoicles.

Head of the Woodpecker.

that feed on fruit and nuts, as Parrots, and in Woodpeckers.
The bill, or rather mouth, of Ducks and Geese is lined by
a tender membrane, in order that they may be partially

What is the length of the Intestine of the Ox? Of the Sheep? Give the propor-
tional length of Intestine in Carnivorous Animals. 844. What difference in the Liver
between flesh and herbivorous animals? 345. Why are Birds destitute of teeth?
What Birds have the hardest bills? What peculiarity in the lining membrane of the
mouth of Ducks, etc. ?

190

HITCHCOCK'S ANATOMY

Fig. 194.

c

s^^R /

,_„„...™.i- 0

Wi~ ^^^^^^^

h .1, J| ^"'"'^ ^^

i mi. ^^^^'^

M
h

fn

'J- — —
o ~..,

Digestive Apparatus of Fowl. a. Esophagus. &. Crop or Ingluvles. c. Pro-
ventriculus. d. Gizzard, e. Liver. /. Gail-Bladder, g. Pancreas, h. Duodenum.
i. Small Intestine. k. C.'eca. I. Large Intestine, m. Ureter, n. Oviduct.
o. Cloaca.

guided in the selection of their food from the soft mud by the
sense of touch.

346. Stomach of Birds. — The Gizzard. — The true
stomach of birds consists of two divisions. There are, how-

846. State the usual cumber of stomachs in Birds.

AND PHYSIOLOGY. 191

6yer, three enlargements of the alimentary canal, all of which
prepare the food for assimilation. The first of these is the
"Ingluvies" or "Crop," where the food is softened by the
mucous secretion of the lining membrane. Then as it passes
along into the " Proventriculus,"' it receives tiie gastric juice
from the gastric glands which line it. The second stomach,
the "Gizzard," is round and flat and made up of powerful
muscular fibres, except in birds of prey, where it is thinner
in texture. In gallinaceous birds its lining membrane is of
a horny consistency, which, with the powerful muscular fibres,
render it an organ of mastication to granivorous birds. Gravel
and angular stones are purposely swallowed by these birds
to aid in the digestive or grinding process.

847. Teeth and Jaws of Reptiles.— Reptiles need teeth
only to seize and retain their prey, since whatever food is
taken by them, is swallowed without mastication, which is
one reason why the iaws and

^1 ^ ^ / FiG. 195.

throats ot serpents are so
very capacious. A peculi-
arity in their bony construe- ^^^^^^R^^^^^

tion renders this possible, *^- ^^^^^^^^^^^^^w~ '

for the jaw is not made \^^ ^^^*^^^^^^^^^

up of one or at most two ^^^^ If^^

pieces as in mammals, but of ^^^^^^i^^^^^^

several segments, which rea- „■ j.

dily move one upon another, Head of the Rattlesnake, mi. Lower

as if with different articula- '^^^- *• Tympanic Bone. ma. Mastoid

Bone. m. Upper Ja%v.

tions.

848. The Tongue .—The Tongue is used as an instrument
for the capture of prey by many reptiles. Frogs and Sala-
manders are able to thrust it out with great rapidity and

Give the names of each. Describe the Gizzard Why are e:ravel and stones swallowed
by granivorous birds ? Which is the true stouiacli ? 847. What is the only use of teeth
in reptiles? State the reason why the jaws are so capacious. Of how many bones are
they frequently made up ? 848. Of what use is the tongue to some reptiles?

9

192 HITCHCOCK'S ANATOMY

coil it upon insects or any other object. This property, to*
gether with the adhesive mucus found upon it, makes it for
these animals a very serviceable apparatus in obtaining
food.

349. Esophageal Teeth. — In many animals of this de-
scription the Esophagus is lined with bony processes pointing
downwards, called Esophageal teeth, which greatly aid in
swallowing the large masses which^they are accustomed to
force into their stomachs.

350. Stomach. — Length of Intestine. — The Stomach
seems to be only a dilatation of the Intestine. In many
species it is divided into two cavities resembling those of a
bird, (Fig. 196) : the first a Gizzard, or an organ made up
of stout muscular fibers, and the second a thin walled and
secreting cavity. In Crocodiles it is round, and the muscular
coat is very thick, in order to reduce to a digestible size
the coarse food which it so greedily devours. The length
of the intestine in most reptiles is about twice the length
of the body ; in Lizards, however, it is only about the
same length as the body. A cloaca or additional rectum
is sometimes found in these animals, as is the case among
birds.

351. Stomach and Intestine of Fishes — In many Eishea
the intestinal tube extends from the mouth directly through
the animal without any enlargement for the stomach, or any
convolutions, as is the case with all the animals thus far con-
sidered on this subject, and with which no organ of secretion
is connected, except the liver. The intestinal canal, however,
is generally more or less convoluted, and ordinarily it is short.
In the Shark the stomach is parceled out by constrictions and

With what is it covered, that renders it more serviceable as an instrument of capture ?
849. What is said of Esophageal teeth? 350. Is the stomach a simple or complex cav-
ity ? What is the average length of intestine among reptiles ? What is said of a cloaca?
851. In what condition is the stomach found in most fishes? What peculiarit/ is met
withiu the Shark?

AND PHYSIOLOGY
Fig. 196.

193

Anatomy of the Common Snake. I. Tongue, ce. Esophagus, i. Stomach, i'. Small
Intestine, cl. Cloaca. /. Liver, o. Ovary, o'. Egirs. t. Trachea, p. p'. Lungs, vt.
Ventricle, e. e'. Auricles, a. ad. a'. Aorta, aa. Carotid Arteries, v. vc Venae Cavas.
vp. Pulmonary Vein.

inversions into several divisions with valve-like appendages
between them.

352. Liver.— Fishes have usually a large soft Liver com-
pletely saturated with an oil. Its form is various, but is

852. SjMjak of the Liver of fishes.

]94

HITCHCOCK'S A N A T O if Y

often imperfectly divided into two lobes. The oil that is ex-
pressed from the liver of the Cod Fish, is often used with
great efficacy in the early stages or symptoms of consumption.
Fig. 197. 353. Pyloric Appcnclagcs.

— In many fishes with bony
skeletons there is found a cu-
rious set of gland- like organs
called Pyloric appendages.
They vary in number from
two in the Plaice, to two
hundred in the Mackerel, and
always either encircle the
pylorus, or are found near
the upper end of the intestine.
These appendages are inva-
riably absent in those fishes
which have an imperfectly
formed stomach, and by some
are considered as analogous
to a Pancreas in function.

354. Salivary Glands.—
Salivary Glands are wanting
in fishes, but their place is
supplied by an increased de-
velopment of the mucous
glands of the mouth.

855. Digestive Organs in
the Invertebrates— In the
Polyps of the Radiate ani-
mals, we have the simplest
form of digestive apparatus,
viz., a simple sack, with a
mouth to receive the food
and to disgorge the refuse, as is seen in Fig. 198, A. Other
Polyps, however, have two openings in their stomach or sack,
as shown in Fig. 198, B.

Digestive Apparatus of a Beetle, a.
Head. h. Crop and Gizzard, c. Biliary
Vessels, d. Intestine, e. Secreting Or-
gans.

AND PHYSIOLOGY.

Fig. 198.

195

Fiff. 199.

Digestive Apparatus of Unicellular Animals.

356. The Hydra. — Fig. 199, an unicellular animal^ is an
example where the simplest sort of digestive organs is ex-
hibited. The animal is little
else than a gelatinous sac,
and if it be turned inside out
digestion will still go on.
Thus, '-notwithstanding the
simplicity of its structure,
this creature feeds not merely
upon algae, but upon young
active animalcules, the young of
crustaceans, etc. ; any one of
these, when they happen to
came in contact with one of
the tentacular filaments, be-
ing usually retained by
adhesion to it. As this
filament shortens itself, all

Hydra or Fresh Water Polyp,
trance and Exit to Stomach.

a. En'

the surviving filaments ap-
ply themselves to this captive
particle, so that it becomes gradually inclosed, and grad'

356. What is the process of digestion in the hydra ?

196 HITCHCOCK'S ANATOMY

ually shortening, so as at last to bring the prey close to the
surface of the body. The spot with which it is brought in
contact, then slowly retracts, and forms at first a shallow de-
pression, gradually becoming deeper and deeper, into which
the prey sinks little by little, for some time, however, con-
tinuing to project from the surface. The depression at last
assumes a flask-like form, by the drawing in of its margin,
and finally its edges close together, and its prey is entirely
shut in. This gradually passes to the center of the. body,
where its soluble parts are dissolved, whilst in the mean time
its external portion recovers its pristine condition."

857. Other Radiates have an alimentary canal more com-
plicated, having a stomach and caecal appendages that appear
to perform the office of a liver. Some of the Echinoderms
have teeth; in the Echinidse is a curious apparatus in the
mouth called Aristotle's lantern.

858. Another form of the digestive apparatus consists of a
central cavity, with branches extending through every part
of the body. Fig. 200 shows this in one of the Articulated
animals^ an Arachnoid Crustacean, the Ammothea pycnog-
onoides. This arrangement is found in several other classes
of the Invertebrates.

859. The Crustaceans are generally furnished with two
upper jaws, called Mandibles, which move laterally ; and be-
hind these, two pairs of weaker and softer lower jaws, which
are sometimes changed into suckers and legs. The higher
branches are always provided with prehensile organs for seiz-
ing the food, which are arranged in pairs.

360. These are best seen in the Lobster, where they are
enormously developed, projecting in front of the eyes a dis-
tance nearly equal to that of the length of the whole body,
and each extremity is furnished with a powerful pair of pincers.
Some of the higher Crustaceans have a sort of horny teeth
implanted in the coats of the stomach which are worked by a

359. What are the jaws of crustaceans ?

AND PHYSIOLOGY,

197

Fig. 200.

Digestive Organs of Ammothea pycnogonoides (Crustacean), a. Esophagar 5. Stom*
fcch. c. Intestine, d. Digestive Cavity of the Jaws. e. Digestive Cavity of the Legs.

powerful set of muscles, which help in the reduction of the
food. These teeth are found in the Lobster's stomach. The
stomach of the Leech is very capacious, being nearly the size
of the whole body. The same is essentially true of the com-
mon Earthworm, "which is an Annelid. In many insects
salivary glands are present, and in such cases they are placed
at the commencement of the alimentary canal. The different
parts of the alimentary canal in insects ''may be properly
distinguished in the following manner. The first portion is
the Esophagus, muscular, occupying the three thoracic seg-
ments and often dilated at its posterior part into a crop
(Ingluvies) and muscular gizzard (Proventriculus). Some-
times there is appended to the Esophagus a sucking stomach,

198

HITCHCOCK'S ANATOMY

Fig. 201.

Aplysia (Mollusc) laid open to show the viscera, a. Esophagus, c. Salivary Glands,
c/. Cephalic Ganglion, e. Esophageal Ganglion. /, g-. First Stomach or Crop. A. Third
or True Stomach, i. Gizzard, k. Intestine. I. Liver, m. Posterior Ganglion, n. Aorta,
o. Hepatic Artery, j)' Ventricle of Heart, q. Auricle, r, s. Branchiae or Gills. ■«►
Lower Intestines, v. Ovary.

AND PHYSIOLOGY. 199

cotisisting of a more or less pedunculated thin walled vesicle,
which is multiplicated on itself when empty. The second
portion consists of a stomach (ventriculus) in which the chyle
is formed, and which is continuous at the point of insertion
of the malpighian vessels with the third portion of the digest-
ive canal. This third portion commences by a small and usu-
ally short ileum, which is followed by a colon larger and of
variable length. This last often has a caecum at its anterior
extremity, and terminates posteriorly in a short, muscular
Rectum."

"A considerable number of insects take no food during
their perfect state, the object of their existence being only to
accomplish the act of reproduction. Their jaws are often
very rudimentary, and are fit neither for sucking nor for
masticating."

361. The Annelida have sometimes quite complicated
jaws, even as many as eight or nine, moving laterally. They
have also salivary and hepatic glands, as have many other
invertebrates. These are shown on Fig. 197, which repre-
sents the whole alimentary canal of an insect.

362. The Cephalopod Molluscs have a mouth, two horny
jaws moving vertically in the pharynx, a tongue, an oeso-
phagus, a stomach, a pylorus, and an intestinal canal.

363. In the Cephalophora the jaws move laterally for the
most part. In the whole class we find a biliary apparatus
and generally salivary glands. Fig. 201 shows the digestive
organs of a Gasteropod, the Aplysia. Nearly all the Ceph-
alophora have a longer or shorter fleshy mass attached to
the base of the pharynx that is comparable to a tongue. It
has a longitudinal grove in it, and is sometimes included in a
sheath. It is always covered with horny denticulated plates
and spines, which are very delicate, and arranged in quite
elegant longitudinal and transverse rows. The points of these
spines turn backward, which aids greatly in swallowing.

200 HITCHCOCK'S ANATOMY

364. In some families of the Entozoa — the Cystici, the
Cestocles and Acantliocephali^ — there is no mouth nor proper
intestinal canal, but there are vessels for the circulation of
nourishment which is received directly through the sides of
the bodj, on the principle of endosmosis.

CHAPTEE FOURTH

THE CIRCULATING SYSTEM.— ANGIOLOGY, OR HISTORY OF
THE ORGANS OF BLOOD CIRCULATION.

DEFINITIONS AND DESCRIPTIONS.

365. The Circulatory Org
this system are the Heart,
Arteries, Veins, and Capil-
laries, and are mainly tubes
of various diameters and a
hollow organ, with the double
office of receiving and propel-
ling the blood.

366. The Heart. — The
Heart, or central engine of
circulation, is located in the
thorax or chest, resting by its
lower surface on the dia-
phragm, and somewhat to the
left of the middle line of the
body. It is of a conical form,
made of animal muscular fiber,
the fibers crossing themselves
in at least three directions ;
and it is a singular fact that

an s . — The organs composing

Fig. 202.

An Anterior view of the Heart in a Ver-
tical Position, with its Vessels injected. 1,
Eight Auricle. 2, Left Auricle. 3, Eight
Ventricle. 4, Left Ventricle. 5, Descend-
ing Vena Cava. 6, Aorta. 7, Left Pulmo-
nary Artery. S, The Arteria Innominatri.
9, Left Primitive Carotid. Id, Left Sub-
clavian Artery. 11, Anterior Cardiac Vcs-
Eols in the Vertical Fissure. 12, Posterior
Vessels from the Transverse Fissure. 13,
Maia Trunk of the Pulmonary Artery.

S65. What aro tlie organs used for the circulation of the blood 'i
of the Heart

S66. Give the location

202

HITCHCOCK'S A N A T O 31 Y

^i^- 203. many of the fibers of the heart

anastomose, or join with each
other in many places, as is
seen in Fig. 203. The heart
is a double organ, one side
being called the arterial and
the other the venous, or left
and right hearts, since the for-
mer receives and propels the
pure or arterial blood, while
the latter circulates venous
blood. Again, each of the two sides or hearts are divided
into an auricle and a ventricle. Each of these four cavities
will ordinarily contain about three fluid ounces, making the
whole heart to contain nearly a pint.

867. The Auricles and Ventricles.— The Auricles are
the uppermost cavities of the heart, and are somewhat smaller

Fig. 204.
t]j ac t ac vj

Anastom

Fibers of the Human Heart.

Eight Lung.

Left Lung.

od vc vd a vg^

Lungs, Heart, and Principal Vessels in Man. od. Eight Auricle, vd. Eight Ventricle.
CJ7, Left Ventricle. «, Aorta- ac. Carotid- Arteries, uc. Vena Cava, t, Traehea. «j,

Jugular Veins,, .„.„....._ . . - ...

What are its shape, size, and four cavities called? What is the capacity of an adult
Xieart? ' '

AND r II Y S I O L O G Y .

203

than the Ventricles, or lower ones. The auricles also have
the thinnest walls, and are capable of considerable dilatation,
since by a sudden effort of the body the blood is liable to be
sent in great quantities to the heart, and the veins would be
in danger of rupture were there no elasticity in the receptacle.
The thickened walls of the ventricles give increased power of

Fig. 205.

Vena Cava Sup. Art. rulm. Aorta. Art. Pulm.

1 /

Pulmonary Veins.
Eight Auricle.

Tricuspid Valve.
Vena Cava Inferior.

Eight Ventricle.

.„., Pulmonary Veins.

— Left Auricle.
"= Mitral Valve.

Left Ventriele.

Septum. Aorta.
Theoretical Section of the Heart in Man.

contraction. This is needed because the ventricles drive the
blood from the heart, and the auricles receive it on its return.
The right ventricle, however, propels the blood only to the
lungs, while the left ventricle sends it to all parts of the body
except the lungs. The left auricle receives only the blood
from the lungs, while the right auricle receives it from all the
other parts of the body.

368. Valves of the Heart. — Between the auricles and ven-
tricles are peculiar forms of muscular and tendinous fibers,
resembling cords and pillars, that are termed valves, making
a sort of curtain to allow the flow of blood from the auricles
to the ventricles, but not in the opposite direction. At the

867. Give the essential diflFerences between the auricles and ventricles. Why does the
left ventricle need the thickest walls? 868. Describe the valves which lie between the
aariclea and ventricles.

204

HITCHCOCK'S A N A T O ^.I Y

Fm. 206. point where the arteries are given off

from each ventricle are found (in each)
three crescent-shaped folds of semi-
cartilaginous tissue called Semi-lunar
Valves, to allow the motion of blood in
an outward direction, but to prevent
the return, which is called regurgita-
tion.

369. Pericardium. — In addition to
the fasciae and fatty matter which im-
mediately invest the heart, this organ is enclosed in another mem-
brane in the form of a shut sac, a fibro-serous membrane called

Semi-lunar Valves of the
Ileart closed.

Fig. 207.

Semi-lunar Valves of the Aorta laid open. <7, Corpus Arantii on the Free Border. 5,
Attached Border, c, Orifices of Coronary Arteries.

the Pericardium (meaning about the heart). This contains a
small quantity of a fluid like water, so that the heart actually
floats in a liquid, and does not rest firmly upon any hard sur-
face. The pericardium not only exists as a loose sac about
the heart, but it is reflected upon it where the vessels are
given ofi" ; covering it in the same manner as the fasciae cover
and protect the muscles.

370. Arteries — Tlicir Coats. — The Arteries are tough and
cylindrical tubes which convey the blood from the heart to the
different parts of the body. They are made up of three mem-

Describe the semi-iunarVaircs nnd their location. SCO. What is the sac called that
surrounds the heart ? What fluid does it contain? How mucli of it is there? Is the
pericardium attached at all to the heart? 8?0. Of how many coats are the arteries com-
poaed?

AND PHYSIOLOGY.

Fig. 208.

205

Anterior
Tibial

Artery.

Art.
Pediosa.

Arterial System in Man.

Posterior

Tibial

Artery.

Peroneal

Artery,

braneSj of which the middle one deserves especial attention.
This is an elastic coat composed of yeitow fibrous tissue (Fig.
209), in order, as we shall presently see, to aid in the circu-

Describe eacli one and their pecnliar value.

206

HITCHCOCK'S ANATOMY

Highly Magnified Portion of the Middle Coat of

the Arteries.

^1(^-209. lation of the blood.

'-'^^^<vi\m V The inner one is smooth

and of a serous charac-
ter, for the ready pas-
sage of the blood over
it. The arteries (all
above aV^h inch in
diameter) are nourished
by a capillary net- work
which is made from ad-
joining blood-vessels. ISTerves are distributed to some arteries,
but ordinarily they only accompany them.

371. The Aorta. — The arteries sent to every portion of
the body from the left ventricle proceed from one trunk,
called the Aorta, meaning a starting-point. It is nearly an
inch in diameter, and ascends in a perpendicular direction
for about two inches, when it mates a curve upon itself, and
descends through the thorax and abdomen until it reaches
the fourth lumbar vertebra, when, as is the case with most
of the large arteries, it divides into two branches of equal
size. Between the curve or arch of the aorta and the heart
no branches are given off, but from the summit of this arch
to the subdivision in the abdomen a great number of branches
are distributed to the different portions of the chest and ab-
domen.

372. Description of Particular Arteries — Innominata
— Carotid — Subclavian — Axillary — Brachial — Ulnar Ra-
dial— Palmar Arch. — The first branch arising from the sum-
mit of the aortic arch is the large one called the Innomi-
nata, or nameless artery. Next comes the Carotid, and both
distribute themselves to the head and upper extremities.

8T1. What is the Aorta? What does the word aorta mean? Give its course till it
eubdivides. Where does it divide into the common iliacs? 872. Where are the, In
nominata Arteries? The Carotid?

AND P H YSIOLOGY

Fig. 210.

207.

A View of the Heart, with the Great Vessels of the Neck in Situ. 1, Eight Ventricle
of the Heart. 2, Eight Auricle. 3, Left Ventricle. 4, Left Auricle. 5, Pulmonary
Artery. 6, Arch of the Aorta. 7, Descending Vena Cava at its entrance into the Eight
Auricle. 8, Ascending Vena Cava. 9, Thoracic Aorta. 10, Arteria Innominata. 11,
Eight Brachio- Cephalic Vein. 12, Left Brachio-Cephalic Vein. 13. Section of the Sub-
clavian Artery. 14, Section of the Sub-Clavian Vein. 15, 15, Primitive Carotid Ar-
teries. 16, 16, Internal Jugular Veins. 17, 17, External Jugular Veins. Between
these Veins is seen the Section of the Sterno-Cleido-Mastoid Muscle. 18, The Trunk
formed by the Superficial Cervical Veins, known sometimes as the Anterior Jugular
Vein. 19, A Branch from it to the Facial. 20, Main Trunk from the Inferior Thy-
roid Veins. 21, Superior Thyroid Vein. 22, Transverse Cervical Artery* and Vein.
23, Lingual Artery and Vein. 24, Facial Artery and Vein.

The Innominata on the right verj soon becomes the Sub-
clavian, after which the corresponding arteries of both arms
receive the same name. The Sub-clavian Artery, as its ety-
mology implies, lies directly beneath the clavicle until it
reaches the axilla, or arm -pit, where it receives the name of

The Sub-clavian ? The Axillary ?

208

HITCHCOCK'S ANATOMY

Fig. 211.

30 29'

A Yiew of the Arteries of the Neck and Shoulder. 1, Primitive Carotid Artery. 2,
Internal Carotid Artery. 8, External Carotid Artery. 4, The Superior Thyroid Artery.
5, Branches to the Muscles. 6, Main Branch to the Gland. 7, Inferior Pharyngeal Ar-
tery. 8, Lingual Artery. 9, Facial Artery. 10, Its Branches to the Sub-Maxillary Gland.
11, Sub-Mental Branch. 12, Principal Branch of the Facial as it goes over the Jaw.
13, Occipital Artery. 14, Branches to the Muscles on the Back of the Neck. 15, Main
Trunk to the Occiput. 16, Posterior Auricular Artery. 17, A Branch cut ofiF, which
goes to tho Parotid Gland. 18, Origin of the Internal Maxillary Artery. 19, Origin of
the Temporal Artery. 20, Origin of the Anterior Auricular. 21, The Sub-Clavian. 22,
Origin of the Internal Mammary. 23, Trunk of the Inferior Tliyroid, from M'hich arise
in this subject the Anterior and Posterior Cervical Arteries. 24, Branch of tho Inferior
Thyroid going to the Thyroid Gland. 25, Anterior Cervical going up the Neck. 26,
Posterior or Transverse Cervical. 27, Branches to the Scaleni and Levator Scapulas
Muscles. 28, The Superior Scapular Artery. 29, The Thoracica Superior of the Axil-
lary Artery. 30, A Branch to the Deltoid. 31, Eecurrent Branches of the Intercostals.

Axillary Artery. Then as it passes along the inner side of
the humerus it is called the Brachial, until it has passed be-
yond the inner side of the elbow, where it is divided into the
Ulnar and Radial, corresponding in position and direction to

Where are the Brachial, Ulnar, and Eadial Arteries ?

AND PHYSIOLOGY

209

the ulna and radius. Some-
times, however, the branch-
ing takes place higher up, as
is seen in cut 212. When
these have fairly passed the
wrist, they both join again in
an artery which describes a
curve at the base of the meta-
carpus crossing the palm of
the hand, and called the Pal-
mar Arch. Small branches
are given off from this which
supply the different parts of
the hand, including the fin-
gers and thumb.

373. Distribution of the
Carotids — Vertebral — Circle
of Willis. — The common Ca-
rotid Arteries, one on each
side of the neck, pass upwards
from the innominata and sub-
clavian nearly as far as the
angle of the jaw, when they
divide into the internal and
external carotids, the latter
furnishing blood to the face,
and the former to the brain and
back part of the head. The
Vertebral Artery is also giv-
en off from the sub-clavian,
which, passing backward, en-
ters the spinal column at the
sixth cervical vertebra, and

Deep-Seated Palmar Arch

Fig. 212.

Arteries of the Arm, 1, Termination of
the Axillary Artery. 2, The Brachial Ar-
tery. 8, 3, Eadial Artery. 4, 4, Ulnar Ar-
tery. 5, A Eecurrent Branch. 6, Anterior
Interosseous Artery. 7, Superficial Pal-
mar Arch formed by the Ulnar Artery. 8,
9, The Anastomosis of the two Arteries, much enlarged.

, What is the Palmar Arch ? 873
ward to the head.

Give tho branches of the Carotid as it passes up*

210

HITCHCOCK'S ANATOMY

passing through a foramen or opening in the transverse process
of each of these vertebrae, at last reaches the posterior portion
of the brain. This artery in the brain meets with the termi-
nal branches of the internal carotid, so that the blood can
easily reach the brain from either direction. By this ar-
rangement, if, from pressure or accident, the flow of blood
to the brain in either of these channels should be obstructed,
the other would supply it ; for sensation and consciousness

Tig. 213.

Circle of Willis. 1, Vertebral Arteries. 2, 3, Anterior and Posterior Spinal Arteries.
4, Posterior Meningeal Artery. 5, Inferior Cerebellar. 6, Basilar. 7, Superior Cerebel-
lar. 8, Posterior Cerebral. 9, Branch of Carotid. 10, Internal Carotid. 11, Ophthalmic
Artery. 12, 13, Cerebral Arteries. 14, Anterior Communicating Artery.

entirely cease if the brain be deprived of its arterial blood.
This arrangement is called the " Circle of Willis" from its
discoverer.

What arteries does the Vertebral communicate with in the brain ? What Is the ser-
vice of this arrangement?

AND PHYSIOLOGY

211

374. Thoracic Aorta— Abdominal Aorta — CcBliac Axis —
Gastric, Hepatic, Splenic, Renal, Mesenteric, and Lum-
bar Arteries. — After the aorta fairly commences its descent
— called the Thoracic Aorta — several small branches are given
off from it which send nourishment to the heart and lungs, and
next a pair which are distributed to the diaphragm. Then

Fig. 214.

A View of the Abdominal Aorta and its Branches. 1, 1, The Diaphragm. 2, Foramen
Quadratum and Section of the Ascending Vena Cava. 3, Foramen Esophageum and
Section of the Esophagus. 4. Foramen Aorticum in the Crnra of the Diaphragm. The
Phrenic arteries a -e. seen going to the Diaphragm. 5, Capsuloe Ecnalcs. 6, The Kid-
neys. 7, Abdominal Aorta. S, Phrenic Arteries. 9, Ccelic — giving- off. 10, The Sple-
nic. 11, The Gastric. 18, The Hepatic. 1.3. Section of Superior Mesenteric. 14, Emul-
gent Arterie.'J. 15. Spermatic Arteries. IG, Inferior Mesenteric. 17,11, Lumb.ar Arteries.
18, Division of the Abdominal Aorta. 19, Its last Branch — the Middle Sacrdl. 20,
Primitive Iliacs. 21, Ureters — in their Position to the Arteries. 22, Internal Iliacs.
2-3, External Iliacs. 24, Circumflexa Ilii. 25, Distribution of the Epigastric. 26, Blad-
der distended with Urine. The Vesical Arteries are seen near it.

S74. T7hat are the first branches of the Thoracic Aorta ?

212

HITCHCOCK'S ANATOMY

Fig. 215.

we meet with a large trunk
given off just below the dia-
phragm, about half an inch
in length, called the Coeliac
Axis, which gives origin to
the Gastric artery supplying
the stomach, the Hepatic,
running to the liver, and the
Splenic furnishing blood for
the spleen. Below this we
find the Renal arteries, sup-
plying the kidneys, and the
Superior and Inferior Mesen-
teric Arteries, which give
blood to the intest'nes, and the
Lumbar Arteries, terminating
in the external muscles of the
abdomen.

375. Iliac Arteries — Fe-
moral, Popliteal, and Tib-
ial Arteries— Dorsalis Pe-
dis.— As already mentioned,
the aorta divides into two
branches opposite the fourth
lumbar vertebra, for the
supply of the lower extrem-

A Front View of the Femoral Artery, as
■well as of the External and Primitive

Iliacsofthe Eight Side. 1, Primitive Iliac Artery. 2, Internal Iliac Artery. 3, Exter-
nal Iliac Artery. 4, Epigastric Artery. 5, Circumflexa Ilil Artery. 6, Arteria Ad Cii-
tcm Abdominis. 7, Commencement of the Femoral just under the Crural Arch. 8,
Point v.-here it passes the Vastus Internus Muscle. 9, Point where It leaves the Front
of the Thigh to become Popliteal. 10, Muscular Branch to the Psoas and Iliacus. 11,
External Pudic Artery cut oflF. 12, Origin of the Internal Circumflex. 13, Profunda Fe-
moris. 14, Muscular Branch. 15, 1 6, Artery to the Vastus Externus Muscle. 17, Artery
to the Pectineus and Adductors. 18, First Perforating Artery, 19, 19, Muscular Ar-
teries. 20, 21, Anastomotica. 22, Superior External Articular. 28, Middle Articular.
24, Inferior External Articular. 25, Inferior Internal Articular.

Describe the Cceliac Axis.
bar Arteries ?

Where are the Gastric, Hepatic, Splenic, Eenal, and Lum-

AXD PHYSIOLOGY

213

ities. These are the com- ^^^- ^i^.

mon iliacs, from being near
the ilium, and each of them
soon subdivides into the Ex-
ternal and Internal Iliac, the
former of which supplies the
greater portion of the leg
with blood. As soon as it
passes over the pubis it be-
comes the Femoral Artery,
which at first is quite exter-
nal, lying just beneath the
skin and upon the pubis ; but
as it passes down the femur it
plunges deeper and deeper into
the soft parts until it appears
behind the knee, where it re-
ceives the name of the Pop-
liteal Artery. This is only a
few inches in length, and at
the upper extremity of the
tibia divides into the Anterior
and Posterior Tibial Arteries.
The former runs along the
inner side of the tibia and
over the tarsal bones, until it
reaches the metatarsus, when
it becomes the Dorsalis Pedis,
which gives off branches to

Lower End of the same Artery on the Popliteus Muscle. 8, Point of Bifurcation into tho
Posterior Tibial and Peroneal. 4, Superior Internal Articular Artery. 5, Superior Ex-
ternal Articular Artery. 6, Middle Articular Artery. 7, Inferior Internal Articular Ar-
tery. 8, Inferior External Articular Artery. 9, Branch to the Head of the Soleus Mus-
cle. 10, Origin of the Anterior Tibial Artery. 11, Origin of the Posterior Tibial Artery.
12, Point where it passes behind the Annular Ligament to become the Plantar. 13, 14,
15, Muscular Branches. 16, Origin of the Peroneal Artery. IT, 17, Muscular Branches.
18, 18, Anastomosis of the Posterior Tibial and Peroneal Arteries near the Heel. 19>
Muscular Branch from the Anterior Tibial.

875. What do the common Iliac Arteries become as soon as they cross the pubis?
Give tha location of the Femoral, Popliteal, Tibial, and Dorsalis Pedis Artery.

A View of the Arteries on the Back of
the Leg. The Muscles have been removed
so as to display the Vessels in their wholo
length. 1, The Popliteal Artery, cut off
so as to show the Articular Arteries. 2f

214

HITCHCOCK

ANATOMY

each of the toes, and supplies the upper part of the foot with
blood. The Posterior Tibial Artery follows upon the back
side of the leg a corresponding course to the anterior tibial,
and supplies the sole of the foot and toes with blood.

376. Capillaries.— The arteries just described area few
only of the principal ones, since at nearly every inch of their
course larger or smaller vessels are given off according to the

Fig. 217.

^^P

a

^^^^^s

M

^^^S

s

Varieties of Capillaries, a, Those around Fat Cells.
Aleuibrajie. d, Skin of Finger.

B, In Muscle, c, In Mucous

nature of the part to be supplied with blood, and, with a few
exceptions, such as the one in the head (circle of Willis),
they all terminate in minute vessels called Capillaries.

377. Diameter of Capillaries — Functions Performed
in them. — These are minute tubes j^oth to -^oVoth of an
inch in diameter, and are always the terminations of arteries.
They are of a uniform size, and very regular in the distribu-

876. How do nearly all the arteries terminate? Where is the only exception ?
St.ite tho diameter of the Capillaries. What of their uniformity ?

877.

AND PHYSIOLOGY

Fig. 218.

215

A Front View of the relative Positions of the Veins and Arteries of the Face and'rfeck.
On the Eight side the Superficial Vessels are seen, and the Deep-seated ones on the Left.
1, Primitive Carotid Arteries. 2, Superior Thyroid Arteries. 3, Internal Jugular Veins.
4, External Jugular Veins. 5, A Branch known as the Anterior Jugular Vein. 6, Supc-
I)erior Thyroid Veins. T, Facial Arteries. 8, Facial Veins. 9, Zygomatic Branch of the
Facial Artery. 10, Nasal Branch of the Facial Vein. 11, Anastomosis of the FacirJ
Artery and Vein with the Ophthalmic Artery. 12, Venous Arch above the Nose. 13,
Frontal Vein. 14, Temporal Vein. 15, Temporal Artery. 16, Frontal Branches of
the Temporal Artery and Vein. 17, Infr.a-Orbitar Vessels. IS, Sub-Aponeurotic Branch
of the Temporal Vein. 19, 20, Venous Anastomosis around the Eye-Lids. 21, Frontal
Branches of the Ophthalmic Vessels of "Willis.

10

216

HITCHCOCK'S ANATOMY

Fig. 219.

tion of their branches, without any increase in their diam-
eter. The only exception to this is where red blood is not re-
quired for the nourishment of
the parts ; as in the white of
the eye, the finger nails, the
tendons, etc., where the ca-
pillaries are too small to allow
the corpuscles of blood to pass
through them. And yet in
many of the capillaries we find
their size to be so small that
the corpuscles could not, if
unyielding, pass through.
But this is readily accom-
plished in most cases by the
flexibility of the corpuscle,
which permits itself to be
doubled up to such an extent
that it will easily pass through
a tube much smaller than its
normal diameter. In the ca-
pillaries the important pro-
cesses of secretion, nutrition,
and the production of a por-
tion of animal heat take place ;
so that there is no place in
the whole body except the
outer coat of the eye, the ten-
dons, the nails, and white
portions of the body gener-
ally where true capillaries are
not found.

A Yiew of the Veins of the Trunk and
Neck. ], The Descending Yena Cava. 2,
The Left Yena Innominata. 3, The Eight
Yena Innominata. 4, The Right Sub-Cla-
vian Ycin. 5, The Internal Jugular Yein.
G, The External Jugular. 7, The Anterior
Jugular. 8, The Inferior Yena Cava. 9,
The External Iliac Yein. 10, The Internal
Iliac Yein. 11, The Primitive Iliac Yeins.

12, 12, Lumbar Yeins. 13, The Right Spermatic Yein. 14, The Left Spermatic Yein.
15, The Right Emulgent Yein. 16, The Trunk of the Hepatic Yeins. 17, The Yena Azy-
gos. 18, The ITemi-Azygos. 19, A Branch communicating with the Left Renal Yein.
20, The Termination of the IIcmi-Azygos in the Yena Azygos. 21, The Superior Inter-
Costal Ycin.

Where are true c^ipillaries not fov.nd ? What takes place in them?

AND PHYSIOLOGY

2V

878. The Veins— Their Coats— Their Yolume.— The Veins
carry the blood from all parts of the body to the heart. Like
the arteries, they have three coats, and the larger veins follow
the same general course as the large arteries. The smaller
veins, however, are much more numerous than the smaller ar-
teries, and are most abundant just beneath the skin. The
whole volume of the veins may be regarded as a large ©one,
with the base at the surface of the body jand the apex at the
heart, so that in these vessels the blood is continually flowing
faster and faster, in consequence of the fluid coming into a
larger channel from small extremities, while the reverse hap-
pens in the arteries. The veins are much thinner in struc-
ture than the arteries, so that after death they most usually
collapse. (See Fig. 218, p. 215.)

379. Locatian of the larg- fig. 220.

er Veins— Sinuses.— As al-
l-eady mentioned, the larger
veins usually lie near the
larger arteries. Both also
frequently have the same
names. But there are sev-
eral remarkable exceptions to
this, as in the vessels of the
brain. Here are but few
veins, but several sinuses or
channels. These are canals
excavated in the dura mater
of the brain with this mem-
brane for an outer coat, and
the serous layer of the true
veins for an inner coat. These sinuses of the Base of the skuii. 1,

mn in difierent directions on Ophthalmic Veins. 2, cavernous Sinus.

. in 1 ^' Circular. 4, 6, Inferior Petrosal. 5, 9,

the mSlde of the skull, and Occipital sinuses. 7, internal Jugular

Vein.

8TS. What course does the blood take in the veins ? Give the coats of the veins.
What is the relative proportion of small veins and small arteries ? What is said of their
aggregate volnrrwe ? 379. Where are the larger veins usually found ? AVhat are Sinuses,
and where are they found ?

218

HITCHCOCK'S a:nato:my

most of them empty into the great veins of the neck. Their
probable service is to afford a free passage of blood from the
brain, even if by excess of arterial action this organ should be
overcharged with blood.

380. Portal System— Use of the Portal System.— An-
other apparent exception to the ordinary system of veins is
seen in what is called the Portal System. This comprises
those vessels which receive their blood from the intestinal
canal, the stomach, and the spleen. As these small vessels
unite into a larger trunk, instead of passing directly to the
heart, they form what is called the Portal Vein, which emp-
ties itself into the liver. This vein ramifies into every part
of the liver, where the blood is again collected by a series of
vessels which unite into several trunks, called the Hepatic
"Veins, and which convey the blood to the heart. The design
of this arrangement is not certainly known as yet, although
it is probable that the blood which returns from the alimentary
canal is not fitted to enter the general circulation until it has
gone through some change in the liver.

381. Origin of the VpIiis
— Valves— Their Discoverer.
— The Veins all take their ori-
gin in the capillary vessels in
every part of the body except
those of the stomach, and in
number and length of tube
greatly exceed the vessels of
the arterial system. In the
lining membrane of the veins,
also, we find a peculiarity
not presented in the arteries.
This is the presence of folds,
so that pouches or bags are
formed, which readily suffer the flow of blood towards the

Of what especial service are they? 880. Describe tho Portal System, What is the
probable use of so marked an exception to the general circulating System? 381.' Where
do the Veins take their origin ? What Is said of the Valves of the Veins?

Fig. 221.

a

Vein laid open to show the Valves.
Vein. &, Valves.

AND PHYSIOLOGY.

219

heart, but almost entirely pre-
vent its passage in an oppo-
site direction. They act in
the same manner as valves in
machinery, although with no
loss from friction, and conse-
quently no necessity of a lu-
bricating fluid. It was the.
discovery of these valves in
the veins which led Harvey,
an English physician, to the
greater discovery of the cir-
culation of the blood. He in-
ferred that the blood could
pass in but one direction
through the veins, and conse-
quently in the opposite direc-
tion through the arteries.

382. Inosculation — Use
of Anastomosis. — The arter-
ies and veins open into each
other (i. e., their own vessels)
very frequently, allowing a
ready flow of blood from one
vessel to the other, even if the
flow does not happen to be in the
most favorable direction from
the center of circulation to the

Fig. 22-2.

The SupeiQcia
1, Axillary Artery, 2, Axillary Vein

Front of
Basilic Vein where

the Upper Extremity,
it enters the Axillary, 4, 4, Portion of the Basilic Vein which passes under the Brachial
Fascia — a portion of the Vein is freed from the Fascia. 5, Point where the Median Ba^
silic joins the Basilic Vein, 6, Points to the Posterior Basilic Vein. 8, Anterior Basilic
Vein, 9, Point where the Cephalic enters the Axillary Vein. 10, A portion of the samw
Vein as scon under the Fascia ; the rest is freed from it. 11, Point where the Median
Cephalic enters the Cephalic Vein. 12, Lower portion of the Cephalic Vein. 13, Mcdwn
Cephalic Vein. 14, Median Vein. 15, Anastomosing Branch of the Deep and Superfldul
Veins of the Arm. 16, Cephalica-Pollicis Vein. 17, Sub-Cutaneous Veins of the J'in-
gers. 18, Sub-Cutaneous Palmar Veins,

Who discovered the circulation of the blood?

220

HITCHCOCK'S ANATOMY

^^^* 223. extremities. This relation of

parts is called Inosculation or
Anastomosis. This arrange-
ment gives a plentiful supply
of blood to every part of the
body, if, by wound or pressure,
the ordinary channel of blood
,to any part should be ob-
structed or completely closed
up. Inosculation is most
abundant in the veins and su-
perficial arteries, since these
are most liable to be thus im-
peded.

383. The Blood — Micro-
scopic Structure — Plasma
or Serum — Red Corpuscles —
White Corpuscles — Propor-
tion of one to the other.—
The blood of the human sys-
tem amounts to about eighteen
pounds, or nearly ten quarts.
Is has a specific gravity a lit-
tle greater than that of water,
is of a bridit scarlet color if

The Arteries and Deep-seated Veins on ^ "^

the Back of the Leg. 1, Popliteal Vein, drawu irom an artery, or dark

2, PoplitealArtcry. 8,4, Vein and Artery | -f ^^i f •

in their relative Position on the Back oi tr ir "^ )

the Kncc-Joiiit. 5, Popliteal Vein on the "v^ith a tastC slightly alkaline,
inner Side of the Joint. 6, Popliteal Ar- t ■• i t ^i ^

tery^vithout and beneath it. 7, Extremity and aU odor rCSemblmg that
of Saphcna Minor Vein. 8, 9, Internal Ar-
ticular Vessels, both Arteries and Veins. 10, 11, External Articular Vessels, both Ar-
teries and Veins. 12, Junction of the Peroneal and Posterior Tibial Veins. 13, A Ven-
ous Branch from the Anterior Tibial Vein. 14, A Vein from the Gastrocnemius. 15,
Anterior Tibial Artery coming through the Interosseous Ligament. 16, Posterior Tibial
Artery. 17, Its two Vcna3 Comites. IS, Peroneal Artery. 19, Its two Venae Comites.
20, Vessels on the Heel.

SS2. What is meant by Inosculation or Anastomosis? What is the service of anasto-
mosis? In what vessels is it most abundant? 383. How much blood is there in a hu-
man adult? State its color and odor.

A X D r II Y s I o L o a Y .

Crystals from Human Blood.

of the breath of the ani- ^ic^- 224

mal from which it is
taken. It penetrates
every solid tissue of the
system, as may be known
by puncturing any part
of the body with even a
pin, when blood is sure
to follow. If it be ex-
amined with a micro-
scope when freshly
drawn, it appears to be
made up of a transparent
liquid called the Serum
or Plasma, and a num-
ber of minute circular bodies, mostly of a red color, called
corpuscles, or minute bodies. This fluid is found, on analy-
sis, to be made up of water, albumen, fibrin, and several salts,
some of which are found in crystals, as is seen in the cut.
After it has been drawn from the body a considerable time, it
separates into a thickened mass called Coagulum, made up of
Pia. 225. fibrin and the corpuscles, while the

serum with the albumen still remains
as a transparent liquid. The Red
Corpuscles prove to bo flattened discs
with both surfaces slightly concave,
and measuring about ^aVuth of an
inch in diameter, and are in reality
nothing but a cell, that is a bag or
sac containing a fluid composed of the
two proximate principles globuline and
hematine. Besides the red corpuscles, there exists another
kind in the blood known as the White or Colorless Corpus-
cles. They are by no means so abundant, when the body is

What is its apjjearanco imdcr the microscope ? How does it conduct itself after stand-
ing a while in an open vessel ? Describe the Eed Corpuscles. Describe the White Cor-
puscles.

Red Corpuscles of Human
Blood, a, Seen on the Surface.
c, Seen in Profile. &, Seen in
a Koll Magnified 400 Diameters.

222 HITCHCOCK'S ANATOMT

in health, a3 the red corpuscles. But in certain diseases, and
especially if there be a wound in any part of the body to be
healed, the white corpuscles are developed at a great rate,
although their abundance ceases when the system is restored
to a sound state again. Their average diameter is nearly
u oV u th of an inch, and they appear to be nucleated cells. The
proportion of the white to the red corpuscles in health is nearly
as 1 to 346. The whole amount of blood corpuscles has been
estimated as high as 65,570,000,000,000.

384. Effect of an Alternate Exposure to Oxygen and
Carbonic Acid . — If the red corpuscles are alternately exposed
to oxygen and carbonic acid they lose their circular form,
and become corrugated or star-shaped, and finally are destroyed ;
and it is calculated that millions of these corpuscles are de-
stroyed at each pulsation of the heart.

FUNCTIONS OF THE CIRCULATOEY SYSTEM.

385. The Main Use of tlie Blood-Vessels— The large
Angle made by the Arterial Branches near the Heart. —
The first and most obvious use of the blood-vessels is to allow
a free and rapid passage of this fluid to every part of the
body. This is evident from the smooth lining of all the ar-
teries and veins, and from the fact that, with the exception of
the large arteries near the heart, the vessels branch off at a
small ano;le from each other, which arranoi;ement offers the
least possible obstruction to the passage of the blood. In the
organs near the heart, as the head and lungs, the blood would
readily pass by smaller vessels and by less force of the heart
in sufficient quantity. But in that case the parts of the body
quite distant from the center of circulation of the blood would

When are the -white ones the most abundant? State the approximate number of bloo(\
corpuscles in one individual. 3S4. What effect has an alternate exposure of oxygen and
carbonic acid upon these ? How many are possibly destroyed at each pulsation of tho
heart ? 385. Give the use of the arteries and veins.

AND PHYSIOLOGY. 223

be imperfectly supplied. And apoplexies and congestions
would be much more frequent than they now are in the vital
organs, if the arteries did not branch off at nearly a right
angle.

386. Why a large Amount of Arteries and Veins. —
The necessity for such a large amount of arteries and veins,
and thair numerous connections with each other, is evident
from the great variety and extent of the tissues, and also
from the great liability to obstruction from inflammations, ac-
cidents, or even the ordinary compression of clothing. But
arranged as these vessels are in the body, it is a very difficult
thing by any mechanical means entirely to check the flow of
blood to any part. But were it not for this system of ample
inosculation the amputation of a portion of the body would
generally produce fatal results.

387. Comparative Capacity of the Arteries and Veins.
— If all the arteries in the body were to be made into a single
vessel, the capacity of it would be much less than that of a
similar vessel made by the union of all the veins. This dif-
ference in capacity will in part result from the feebler char-
acter of the forces which propel the blood through the veins
than through the arteries, and consequently venous obstruc-
tion could not be so easily overcome as if it were in the ar-
teries ; and in order to compensate for deficiency in power, aU
increased amount of tubing is provided.

388. Forces of the Arterial Circulation. — Theinquiry
naturally arises. What are the forces that send the blood
through the circulatory channels ?

389. Contraction of the Heart— Elasticity of the Mid-
dle Coat. — In the first place the contraction of the heart is
the most essential force in driving the blood outwards. This
force has been estimated at thirteen pounds, though the re-

Why do the arteries near the heart branch off at a largo angle? 8S6. Why Is therd 50
large an amount of arteries and veins ? 887. What is the comparative capacity of tha
veins and the arteries ? 358. What are the forces of the circulation ? SS9. What is said
o{ the contraction of the heart ? What is the estimate of the force that it esejta ?

10*

224 HITCHCOCK'S ANATOMY

suit can not be relied on for perfect accuracy ; and that this is
no inconsiderable force may be inferred from the great amount
of resistance that is offered to this current from the ramifica-
tions of the smaller arteries, whereby the velocity is increased
as well as the surface of resistance. It may also be seen by
wounding an artery of medium size, when the blood is sent
out in jets, and sometimes to the distance of several feet.
This, however, is not the whole amount of the propulsive
force in the arterial system, for the middle or elastic coat as-
sists by a secondary action. When the ventricle contracts, or
the heart beats, the blood is driven into the aorta and its
larger branches with so much force, that the middle coat yields
considerably, and the artery is distended beyond its ordinary
size. As soon as the contraction of the ventricle ceases, of
course the blood is forced back towards the heart by the elas-
ticity of the artery. But as soon as it commences to flow to-
wards the heart the semi-lunar valves close at once, prevent-
ing the flow in that direction, so that the whole force of the
artery is expended in driving the blood towards the extremities.

390. Pressure of the Muscles. — Another power which
aids in the propulsion of the arterial blood is the pressure of
the muscles upon the arteries. This is effected by the en-
largement which always takes place in the belly of the mus-
cle whenever it is used. This is not a constant power, acting
only during exercise of the muscles.

891. Forces of the Venous Circulation.— The agencies
by which the blood is returned to the heart are not so well
known as those just considered. The valves in the lining
membrane of the veins seem to be a contrivance to supply the
deficiency of power to drive the blood back.

392. Pressure of the Muscles. — The pressure of the
muscles, without doubt, is another important impulse in

When can the forces of the circulation in arteries be well seen? How does the mid-
die coat assist in this work? Of what use are the semi-lunar valves? 890. How does
the pressure of the muscles aid in the circulation? 891. How do the valves aid in the
venous circulation ? 892. Does muscular pressure aid in this ?

AND PHYSIOLOG"?. 225

aidinor the return of blood towards the heart. For, as in the
aorta, its elasticity forces the blood, first against the semi-
lunar valves and then onwards through the arteries, so the
muscles, pressing upon the veins, urge the blood into the
pouches or valves on their inner coat, which, preventing re-
gurgitation, assist in returning it towards the heart.

393. Respiration. — Respiration is another cause that
greatly aids in emptying the veins. In some persons a dis-
tinct fullness or pulsation of one of the veins of the neck is
noticed during each inspiration. This is produced by the
partial vacuum made by the act of inhaling air ; that is, as a
pressure is produced on all parts of the body by the atmos-
phere, not only a rush of air is made into the mouth, but the
blood is forced into the heart by the same cause. And could
we examine all the large veins of the body during inspiration,
without doubt we should see the blood returning rapidly in
them at each inhalation of air.

394. Affinity of Venous Blood for Oxygen. -The affinity
or desire of venous blood for the oxygen, and the arterial for
the tissues, are important causes in the circulation, and es-
pecially in the capillaries. It is a principle well known in
physics, that if two fluids of different degrees of affinity for a
third fluid meet each other in a capillary tube, the fluid hav-
ing the strongest affinity for the third substance will either
partially or wholly force out the other fluid. This takes place
equally well through porous substances, membranes, or capil-
lary tubes.

395. So that when pure air is present upon one side of the
membrane of the lungs and venous blood on the other, the
latter urges itself onward to meet the oxygen, and thus forces
that which is already purified into the pulmonary vessels, and
thence into the heart.

896. The same thing is seen in the capillaries of the ex-

893. How does the respiratory act aid the circulation of the blood ? 394. How does
chemical affinity aid in the circulation ?

226 HITCHCOCK'S ANATOMY

tremities, where the arterial blood, bj its affinity^ for the
healthy tissues, forces along that which is already surcharged
with carbonic acid into the systemic veins.

397. Forces of the whole Circulation.— The forces, then,
which propel the blood through the whole system may be thus
briefly summed up :

1. Contraction of the heart.

2. Elasticity of the arteries.

3. Capillary force.

4. Muscular pressure.

5. Act of inspiration.

6. Arterialization of the blood.

398. Course of the Blood through the Body. — As al-
ready mentioned, the ventricles are the propelling and the
auricles the receiving cavities. Hence, in tracing the course
of the blood through the body, beginning with the left ven-
tricle, we find the current passing through the aorta and ar-
teries to all parts of the body except the lungs. As soon as
it has gone through the capillaries it returns to the right au-
ricle by the different veins, from which cavity it passes to the
right ventricle, and thence to the lungs. After it has received
its due supply of oxygen, it is received by the left auricle,
from which it passes again to the whole system. The parts
of this circle and their order are as follows : left ventricle, ar-
teries, capillaries, veins, right auricle, right ventricle, lungs,
and left auricle. Thus we see that the whole circulation in
man and all mammalia follows through the body a course
represented by the figure 8.

399. Relative Time Occupied by Contraction of Au-
ricles and Ventricles .—The diastole or dilatation of auricles
and ventricles occupies a longer period of time than the cor-
responding systole, or contraction. If we divide the whole

397. Give a. synopsis of the circulatory forces. 89S. Giro tLo course taken by th»
"blood as it circulates through the body. By what figure may it be represented? 899.
What is the systole and diastole of the heart ?

AND PHYSIOLOGY.

227

Fig. 226.

3 4-

ft

7

5

1

wrist,

or anj

other

artery

of the

body.

sounds

do not

corre-

Auricles.

"Ventricles.

Diagram showing the relative Time occu-
pied by the Contraction of the Auricles and
Ventricles, the converging lines from left to
right indicating the contraction, and the di-
verging ones the dilatation.

portion of time occupied by one pulsation into eight intervals,
we shall find that the auricles employ only one of these in-
tervals in contraction, and the remaining seven by dilatation ;
while the time occupied by the
contration of the ventricles is ^ ^
the same as their dilatation, as
may be seen in the diagram.

400. The Sounds of the
Heart— Cause of the First
and Second Sound.— If the
ear be applied over the heart
of a healthy person, two
sounds will be heard, one
of which corresponds in time
with the pulsation noticed
at the
large
These

spond to each other in intensity or duration, but are some-
what indefinitely represented by the sounds given to the mono-
syllables '' lub" and "dup;" the first a long and heavy
sound, and the second a short and light one. The first sound
is undoubtedly caused by the contraction of the heart, the
rush of blood, and the impulse of the organ against the side
of the chest ; while the second is the clicking of the semi-
lunar valves as they close at the commencement of the aorta
after the ventricular contraction. That the last sound is due
to this cause is proved by an experiment performed on a dog,
of introducing a hook through the aorta, and holding back one
of these valves, when the second sound entirely failed.

401. Number of Pulsations per Minute. — The number
of pulsations of the heart varies considerably at difierent pe-
riods of life. Thus the following table shows the average
number of pulsations each minute at different ages :

Give the relative time occupied by the contraction and dilatation of the auricles and
ventricles. 400. What two sounds are made at each complete pulsation of th? heart ?
Give the causes of the first eound. What is the last sound owing to ? What proof of
it?

228 HITCHCOCK'S ANATOMY

New-born infant 130 to 140

During the 1st year 115 " 130

" " 2d " 100 " 115

From the 7 th to the 14th year 80 " 90

" 14th " 21st " 75 " 85

" 21st " 60th '• 70 " 75

Oldage 75 " 80

402. Causes affecting the Pulsations. — Muscular exer-
tion has a considerable influence upon the rapidity of the con«
traction of the heart. So also has the position of the body,
whether sitting, lying, or standing. The time of day or
night likewise has an important influence, the highest number
of pulsations being found at noon, and the fewest at mid-
night.

403. Use of the Corpuscles. — The function of the Red
Corpuscles seems to be to convey oxygen to the tissues, and
as this is the agent which is continually promoting the change
or waste of the system, these corpuscles seem to be the great
agents for disassimilating the tissues and the blood itself The
colorless or white corpuscles seem to be the agents by which
the repair of the body is efiected, since they are greatly aug-
mented in number when there is a large wound to be healed,
or when there is a great amount of internal or external in-
flammation.

403a. Statistics . — In an ordinary life of a man the heart
beats at least 3,000,000,000 times, and propels through the
aorta one half a million tons of blood. ^

HYGIENIC INFERENCES.

404. But few Diseases of the Circulatory Organs. —
1. Though the blood-vessels are so constantly in use, and so
easily excited by every muscular movement and mental emo-
tion, yet they are afiected by only a few diseases, and many

401. State the number of pulsations of the heart at diflFercnt periods of life. 402. What
causes modify the number of the pulsations ? 403. What is the probable business of the
Kcd Corpuscles? What of the White? 404. Are there mauy diseases of the Circulatory
organs?

AN-D PHYSIOLOGY. 229

of these affections, which seem to be diseases of the heart, are
merely sympathetic, and the difficulty lies in other organs.

405. Avoidance of sudden Efforts.— 2. But those per-
sons who have a tendency to diseases of the heart, sympa-
thetic or organic, should be on their guard against sudden
exertions, and, to as great an extent as possible, avoid mental
anxiety and alarms. Heart diseases are most common late in
life, at or about sixty years of age.

406. Principal Danger from Wounds. — Treatment of
Wounds of Arteries.— 3. The principal danger to be feared
from these organs results from Avounds. If these are in the
arteries, they require prompt attention, but if in the veins,
they need scarcely ever excit3 fear. If an artery be wounded
— which can always be known by the escape of blood in jets,
and not a steady stream — the wound should be either closed,
or the artery pressed upon between the wound and the heart
with so much force as to stop the flow of blood through it.
In case of any such arterial wound it will always be well to
tie a bandage as tight as possible immediately over the wound,
and then compress the artery as already mentioned. If the
wound be on the hand or forearm, the brachial artery may be
found and compressed just above the inner angle of the elbow.
Or if it is desirable to compress the artery still higher up, the
axillary artery may be found in the armpit, where by pressing
outwards, nearly all the blood flowing to the arm may be
checked.

407. Method of Checking the Blood to the Lower Ex-
tremities .—4. If it is desired to check the flow of blood to the
lower extremity, the popliteal artery lies directly against the
femur upon the backside of the knee-jomt, where a compres-
sion of it may be effected with great advantage. Nearer the
heart (in the groin) the femoral artery is found, where it

" 405. What should those persons predisposed to thes© diseases especially be on their
js:TTard against? At what time of life are Heait diseases the most frequent? 406. How
can we distinguish between the wound of a vein and that of an artery? How may ar-
terial hemorrhage be most readily checked in the upper extremities ? 407. How may it
bo checked iu the lower extremities ?

230

HITCHCOCK'S ANATOMY

crosses the os innominatum lying just beneath the skin. Here
an efficient compression may be made, since all the anterior
part of the thigh and the whole of the leg proper, is supplied
with blood from this artery.

408. 5. Except bad wounds, however, a tightly drawn band-
age, directly over the wound, thoroughly wet with cold water,
will check hemorrhage sufficiently, until a surgeon can be
called. i

COMPARATIVE ANGIOLOGY.

409. Heart of Mammals.

Fig. 227,

Circulation in Man. a. Eight Auricle.
h. Eight Ventricle, c. Left Auricle, d.
Left Ventricle, e. Aorta. / Vena Cava.
g. Pulmonary Artery. h. Pulmonary

Veins.

■In all mammals the heart is
divided into four cavities, as
in man. Its form, however, is
more rounded and less elon-
gated. In one species of the
whale this organ is cleft in a
peculiar manner, the division
between the two ventricles
being indicated externally by
a deep fissure in its apex. In
the Ox, Hog, Sheep, and
Goat there are always found
one or two bones in the di-
visions between the ventri-
cles. In most mammals it
is placed more in a right Hne
with the middle of the body,
and not so obliquely as in
man.

403. What treatment will check all ordinary hemorrhages? 409. What is peculiar m
the heart of the Whale, the Ox, the Sieop, and Goat? Where is the heart located it
quadrupeds ?

AND PHYSIOLOGY.

231

410. Aorta and Pulmonary Veins.— The manner in which
the Aorta and its branches are given off varies greatly in these
animals, as may be seen by the cut. The number of Pulmo-

FiG. 228.
D E P

23 23 2 3 7^?^

l^'fU^^'f'

1^

a b a

h a h a ha hah a

Dia^am of the Principal Varieties of the Aorta in its Principal Branches in a, Man ;
B, Elephant c, Cetacea ; d, Bat; k, Carnivora; f. Seal; G, Ruminants; n, Eeptiles.
1, Eight Subclavian. 2, Eight Carotid. 3, Left Carotid. 4, Left Subclavian. 5, Verte-
bral, a, Ascending and b Descending Aorta.

nary Yeins varies upon the different sides of the body, and
is generally according to the number of lobes in the lungs,
the relations of the sides being represented by the formula

3 + 2.

411. Economy of Diving Animals. — In diving animals the
vena cava is capable of great dilatation, in order to contain an
unusual quantity of blood which accumulates there when the
animal suspends respiration under water, since it can not be
purified except in the lungs. Still further protection to the
heart in diving animals is seen in the vena cava ascendens,
where a circular muscle, by its contraction, can completely cut
off the flow of blood to the heart Fig. 229.

from the lower extremities.

412. Blood Corpuscles of
Mammals — Wonder Nets. —

The blood of mammals, for
the most part, presents small
round, disc-shaped corpuscles,
similar to, but smaller than those in man. This is especially

tt

M

c^

B A

Eed Corpuscles of the Or. A, In their
Natural State, a, Seen in Profile. &, Seen
on the Surface. B, Altered Corpuscles.

410. What is peculiar about the aorta and pulmonary veins in many mammals ? 411,
What is the arrangement of the vena in diving animals ?

232

HITCHCOCK'S ANATOMY

Fig. 230.

true of ruminants. The largest animals, such as the elephant,
have very small corpuscles. In some of the camels and llamas
the corpuscles are large and somewhat elongated. The same

is true of the dromedary.
Crystalline substances
are found in the blood
of other mammals as
well as man. The an-
nexed cut shows crystals
from the blood of the
Guinea pig.

The distribution ot
the arteries of quadru-
peds is a subject of con-
siderable interest. In
grazing animals, which

Blood Crystals of the Guinea Pig. hold their heads loW, in

addition to large arterial trunks, we find a great number of
very small ones, which are exceedingly tortuous in their course,
called "Wonder Nets." This arrangement is to prevent a too
rapid flow of blood to the head by the force of gravity, which
would of necessity take place when the head is so constantly
in a dependent position. A similar disposition is seen in the
limbs of the sloth and other animals which are like them in
tardiness of movement. In the fore-leg of the lion, where
great muscular force is exerted, the main artery passes through
a perforation in the bone, so as to secure it from obstruction
to the flow of blood by pressure of the rigid muscles.

413. Heart of Birds. — The heart of birds is highly mus-
cular and of very large size in proportion to the bulk of the
body, and in general structure resembles the same organ in
mammals. The valves of the right ventricles, however, are
supplied with a strong band of muscular fibers, which gives

412. What is peculiar about the blood discs or corpuscles of the larger animals?
"What is the form of nearly all of them ? In what animals ar c they oval ? What are
Wonder Nets, and why are they introduced? 413. What is worthy of note with refer-
ence to the heart of birds ?

AND PHYSIOLOGY

233

additional impulse to the blood as it is forced into the pulmo-
nary arteries The need of this arrangement is to give a full
supply of blood to the lungs, which the ordinary powers of
the heart could not effect.

Fig. 231.

as cl

Arterial System of a Bird.
Arteries of the Grebe, a. Aorta, am, One of its large Branches. It gives off the
Carotid {ac) and Subclavian, is ultimately distributed to the muscles of the chest, and
corresponds to the mammary arteries of mammals, av. One of the Branches of the
Vertebral Artery supplying the Muscles of the Shoulder, ce, Arterial Loops formed by
the Branches of the External Carotid, al. Lingual Artery, t, Trachea, or wind-pipe.
ar, Eenal Arteries, ai, Ischiatic Artery proceeding to the lower extremities, as, Sac-
ral Artery, forming a continuation of the Aorta, and giving origin to the Inferior Mesen-
teric Artery, etc. cl. The Cloaca.

Why do the valves have aa especial muscle ?

234

HITCHCOCK'S ANATOMY

414. Arteries— Wonder i^ets. — The trunk of the aorta is
very short, and after giving arteries to supply the heart it di-
vides at once into two large branches, quite unlike the con-
formation in mammalia. Wonder nets, too, are often found
in birds, and especially in those arteries supplying the brain,
eyes and legs.

Fig. 232. 415. Blood. — The blood of

birds has the highest tem-
perature of the vertebrate
animals— 110° F. The blood
cells, or corpuscles, are al-
ways of an elliptical form and
of a very uniform diameter.
416. Heart of Reptiles.—
The heart of reptiles ordinarily consists of a single ventricle,
Tig. 233. Pig. 234.

®

(D

Pigeon's Blood (red) Corpuscles Magni-
fied 400 Diameters. A, In Natural State.
B, Altered by Acetic Acid.

Blood Corpuscles of the Frog, 400 Diameters.
A, In Serum, a, Fully Developed. l>, Nucleus
with clear contents.

or propelling cavity, and two auri-
cles, or receiving cavities, so that

Circulation in Reptiles, a, Heart, the pure blood is mixcd with tho

fc, Ventricle, c, c, Auricles. impure (or a portiou of it) as it

comes from the lungs, which accounts in part for the general
sluggishness of these animals. The blood corpuscles of rep-
tiles are large and oval, as may be seen in Fig. 234.

414. Into how many branches does the aorta at once divide ? Where are wonder nets
found in birds? 415. Wiiat is said of tho temperature of birds? What of blood-cells ?
416. Describe the heart of reptiles. What is the effect upon the blood? What is tho
size of their blood-vessels ?

AND PHYSIOLOGY

235

417. Blood- Vessels. —The arrangement of Blood- Vessels
is very diverse, since one portion of them breathe bj gills and
another b j lungs, while frogs in their early condition are fur-

FiG. 235.

Carotid
/Artery.

Arches of
the Aorta.
Left
Auricle.

Ventricle

of the

Heart.

Pulmonary

Vein.

Brachial

Artery.

Pulmonary

Artery.

Pulmonary
Artery.
Inferior
Vena
Cava.

Liver and
Vena
Portfe.

Kidneys.

Ventral
Aorta.

Intestines.

Circulatory Apparatus in the Lizard.

417. "Why are blood-vossels arranged differently In many of the reptiles ?

236

HITCHCOCK'S ANATOMY

nished with the former, but in adult age, after passing through
a metamorphosis, have the latter system of respiratory vessels.

418. Heart of Crocodile.
— Crocodiles and turtles ex-
hibit the most perfect form of
heart, for it agrees essentisilly
with that of mammals, as may
be seen in Figs. 236 and 237.
But there is a small opening
just at the outlet of the two
ventricles, so that the pure
and impure blood is mixed.

419. Portal System. -
Reptiles have a double Portal
System, one set of vessels

supplying the kidneys and another the liver.

420. Lymphatic Hearts.— Many reptiles have small sac-
like organs lying just beneath the skin in certain portions of
the body, which, from their containing lymph and showing

Fig. 23T.

i

Pulmonary Artery.
Pulmonary Vein.

Heart of Crocodile, v. Veins, ao, Eight
Auricle, vt Ventricles, ap, Pulmonary
Arteries, a, A Vessel proceeding from the
Ventricle to the Aorta, off, Left Auricle.

Pulmonary Artery.^

Pulmonary Vein. -
Eight Auricle.

Vena Cava.
Left Arch of the Aorta.

Eight Aorta.

Left Auricle.
Single Ventricle.

Ventral Aorta.

Heart of the Turtle.

pulsations, are called Lymphatic Hearts. In the Frog, two
such hearts are situated on the back of the animal, between
the joints of the thigh bones.

41S. What animals of this class have the most perfect furm of a heart? 419. What kind
of a portal system tlo wo find among reptiles? 420 Describe lymphatic hearts.

AND PHYSIOLOGY.

23?

421. Heart of Fishes. — The heart consists of one auricle
and one ventricle, which are covered bj a pericardium, and
the whole organ is very small in proportion to the size of the
whole body, being from 4 ^ o^h
to ToVoth its weight. In the
osseous fishes the heart is
elongated and conical, while
in the Sharks and Rays it is
broader. The ventricle dis-
charges its blood through the
aortic trunk upon the gills.
This trunk divides up into
a large number of minute
branches which ramify upon
the gills, and after the blood
has received its oxygen from
the water, it is collected by
a corresponding set of ves-
sels, and emptied into another
trunk which supplies all the
rest of the body — which trunk
corresponds to the aorta —
thouorh it has no muscular
power to propel the blood along. After it has performed its
office it is collected by a system of vessels similar to veins,
and returned to the auricle.

422. Pulsations in a Minute.— Commonly not more than
twenty or thirty beats in a minute may be counted in fishes,

'Avhile in birds one hundred may be counted in the same
time.

423. Portal Circulation. —In fishes, as in reptiles, there
seems to be a double portal circulation.

Circulation In Fishes, a, Heart, b,
Auricle, c, Ventricle. d. Circulation
through the Gills, or Lesser Circulation.
g, Circulation through the Body, or
Greater Circulation, e, Arteries, f, Veins.

421. Why is the heart of the osseous fillies called a branchial heart ? What proportion
of the body does it constitute ? Give the course of circulation. 422. What number of
pulsations can be counted in the heart of fishes, and what number in birds?

238

HITCHCOCK'S ANATOMY

Fig. 239.

Branchial Artery.

Arterial Bulb.^ \

Ventricle of the

Heart.

Auricle of the

Heart.

Venous Sinus,

Vena Portae,
Liver, «fec.

Intestine.

Vena Cava. —

Branchial Vessels^

Dorsal Artery.

Kidneys.

Dorsal Artery, tit
Aorta.

Circulating Apparatus of the Fish.

424. Accessory Hearts— Caudal Heart. — Among many
fishes are found wbat are termed Accessory Hearts, or small
muscular organs which seem to aid in the propulsion of blood
through the different parts of the body. Thus, in the myxine,
the portal vein is distended into a large sac, which expands
and contracts alternately; and in eels there is found upon

424. What are tha accessory hearts of fishes ?

AND PHYSIOLOGY.

239

both sides of the last caudal vertebra a pulsating organ which
receives the blood from the delicate veins of the caudal fin,
and propels it into the caudal vein, this constituting a true
caudal heart.

425. Fishes' Blood.— The blood of
fishes, almost without exception, is of a
red color, and contains oval and slightly
bi-convex corpuscles. In one family
they are distinguished by their great
size, and thus resemble those of frogs ;
but other families have smaller ones.

Fig. 241.

Smaller Circulation.

Fig. 240.

Blood Corpuscles of a,
Lamprey Eel ; h. Skate.

Branchlo-Cardiac

Canals.

Heart.

Arteries.

Greater Circulation.
Diagram of the Circulation in Fishes.

426. Dorsal Vessel, or Heart of Articulates. — In ar-
ticulata, a vessel or tube passes along the back of the body —
behind the intestines and in front of the chaui of ganglia —
called the Dorsal Vessel, which is divided into as many por-
tions as there are segments of the body. This is really the

What peculiarity in the taU of the eel ? 425. What is the color of fishes' blood, and
what are its corpsucles? 426. What is the Dorsal Vessel of articulates?

11

240

HITCHCOCK'S ANATOMY

Circulatory Apparatus in the Lobster, a, The Heart. 6, Ophthalmic Artery, c, An-
tennar Artery, c?, Hepatic Artery, e, Abdominal Artery. ^ Sternal Artery, gr, Venous
Sinuses, h, Branchiae.

heart of the animal, since by the contraction of its coats the
blood or contained fluid is forced along. Small arteries are
given off from this dorsal vessel all along its course. This

Fig. 243.

Circulation in Insects, a, Dorsal Vessel. J, Principal Lateral Currents. The Arrowa
show the direction of the Fluid.

plan, however, is seldom completely carried out, but is most
fully exemplified in the class of insects which is partly ex-
hibited in Fig. 243.

AND PHYSIOLOGY. 241

427. Ventral Trunk . — The blood which is driven forwards
by this dorsal vessel is collected by a set of vessels which unite
into a large tube called the Ventral vessel, or trunk, which
returns it to the posterior part of the body.

428. Blood of Articulates. — This fluid called blood is a
thin liquid, yellowish brown, red, green^ or even colorless,
and never containing corpuscles ; and the only reason why it
is called blood is, that it circulates like the blood of the
higher animals.

429. Cliylaqueous Fluid. — But besides this fluid there is
another found in the general or abdominal cavity of the body,
which, though not contained in organs expressly designed for
its circulation, yet is rapidly carried thiough the body by
means of the motion of the different segments of the animal,
which in many of this order is incessant. This fluid, unlike
the true blood, is rich in corpuscles and easily coagulated,
which gives it one of the essential characteristics of true blood
in the higher animals. It, however, must probably be re-
garded as the cylaqueous fluid of many of the lower verte-
brata. Scorpions have arteries and veins.

430. Heart and Blood Fig. 244.
of Crustacea.— Amongthe
crustaceans, such as the crab ^
and lobster, we find a vessel ^
much shorter than the dorsal
vessel of most articulata, -^ — ^^ B

which resembles a heart from Blood Corpuscles of tlie Crab. A, Granule

j.t i? J. J.U X 'i. • 1 Cells. B, Nucleated Cells.

the fact that it is a propel-
ling organ and has muscular fibers in its coats. The blood in
these animals is of a whitish or purple color, and the pulsa-
tions of the heart vary in number from fifty-one to two hun-
dred per minute.

427. How Is the blood returned that Is circulated hy the dorsal heart f 42S. Describe
the blood of articulates. 429. What other fluid is found in these animals ? 430, What la
eaid of the heart and blood of the crab and lobster ?

242

HITCHCOCK'S ANATOMY

431. Circulation in Molluscs. — The higher orders of
molluscs show a system of circulating vessels which seem to
be arteries and veins, witli a central vessel answering to a
heart. There is usually a ventricle corresponding to the
right ventricle in man, to send the blood to the respiratory
organ. There is also another cavity which corresponds some-

FiG. 245.

Anatomy of the Snail, a, Mouth. &, Foot. (Z, Lung, e, Stomach. /Intestine, g^
Liver, h, Heart, i, Aorta, j. Gastric Artery. I, Hej»atic Artery, k. Artery of the
Foot, m, Abdominal Cavity, n, Canal conveying the Blood to the Lungs, o, Vessel
carrying Blood from Lung to Heart.

what to an auricle, which receives the blood as it enters the
heart. But with the exception of the vessels carrying blood
to the gills, there are few separate tubes for carrying this
fluid through the body, it being left to circulate by imbi-
bition, or it is effected by means of the lacunar spaces. Fig.
245.

432. Blood of Molluscs.— The blood of these animals is
generally destitute of corpuscles, and is sometimes colorless,
though often white, brown, red, or green.

433. Contractions of the Heart. — The heart does not

431. What are the circulatory vessels in molluscs ? Ho-w is most of the fluid circu-
lated ? 432. What of the blood of molluscs ?

AND PHYSIOLOGY. 243

expand and contract regularly, but in a spiral, screw-like
manner, like the peristaltic motion of the intestines.

434. Circulation in the Radiata and Ppotozoa. — In a
few polyps a vascular system is quite obvious, and may be
inferred in them all. The blood is colorless, and has white
corpuscles. In the Acalephae there exists a circulating fluid,
which is thought by Agassiz and Dana to be merely water,
intended to subserve the purposes of respiration rather than
nutrition. The Echinoderms have one heart, and sometimes
more. The Infusoria have pulsatory cavities, but no system
of circulation.

433. How does the heart pulsate? 434, What is the plan of circulation among the
radiate animals ?

CHAPTER FIFTH

PNEUMONOLOGY, OR HISTORY OF THE ORGANS OF BREATHING.
—THE RESPIRATORY, VOCAL, AND CALORIFIC ORGANS.

DEFINITIONS AND DESCRIPTIONS.

435. Location of Respiratory Organs. — Sympatliy be-
tween the Heart and Lungs. — Within the thorax are con-
tained not only the central organs of circulation, but other
organs closely related, and connected with them, the Respira-

Veln of the Arm.

Eight Lung.

Fig. 246.

Vj t Tj

\ u

Artery of the Arm.
Vein of the Ana.

Left Lung.

vc vd a vg

Lungs, Heart, and Principal Vessels in Man. od. Eight Auricle, vd. Right
Ventricle, "cg. Left Ventricle, a. Aorta, ae. Carotid Arteries, uc. Vena Cava.
t. Trachea, ty, Jugular Veins.

435. What organs are contained in the thorax? What is said of the sympathy be-
tween the respiratory and circulatory organs?

ANATOMY AND PHYSIOLOGY

245

torj. These are not only related by position, but are mutu-
ally dependent on each other for their action. Thus, if severe
disease affect the heart, the lungs are very apt by imperfectly
or irregularly performing their offices, to show their sym-
pathy. In like manner, if the lungs exhibit disease,
sooner or later the heart is sure to manifest its sympathy
with its suffering neighbors.

436. The Lungs, their Shape, their Color, Lobes of
the Right Lung, Capacity of the Right Lung, Amount of

Fig. 247.

A View of the Bronchia and Blood-Vessels of the Lungs as sho-\vn by Dissection,
as well as the relative Position of the Lungs to the Heart. 1, End of the Left Au-
ricle of the Heart. 2, The Eight Auricle. -3, The Left Ventricle with its Vessels.
4, The Eight Ventricle with its Vessels. 5, The Pulmonary Artery. G, Arch of the
Aorta. 7, Superior Vena Cava. 8, Arteria Innominata. 9, Left Primitive Carotid
Artery. 10, Left Sub-Clavian Artery. 11, The Trachea. 12, The Larynx. 13, Up
per Lobe of the Eight Lung. 14, Upper Lobe of the Left Lung. 15, Trunk of the
Eight Pulmonary Artery. 16, Lower Lobes of the Lungs. The Distribution of the
Bronchia and of the Arteries and Veins, as well as some of the Air-Cells of the Lungs,
arc also shown in this dissection.

246

HITCHCOCK'S AI«rAT03IY

Blood ill eacli Lung. — The essential organs of respiration
are the Lungs. These are light solids, two in number, and
occupj nearly four fifths of the cavity of the chest. They

Fig. 248.

An Anterior Yiew of the Thoracic Viscera in Situ, as shown by the Eemoval of their
Anterior Parietes. 1, Superior Lobe of the Eight Lung. 2, Its Middle Lobe. 3, Its
Inferior Lobe. 4, 4, Lobular Fissures. 5, 5, Internal Layer of the Costal Pleura form-
ing the Right Side of the Anterior Mediastinum. 6, 6, The Eight Diaphragmatic Por-
tion of the Pleura Costalis. 7, 7, The Eight Pleura Costalis on the Eibs. 8, Superior
Lobe on the Left Lung. 9, Its Inferior Lobe. 10, 10, Interlobular Fissures. 11, The
Portion of the Pleura Costalis which forms the Left Side of the Anterior Mediastinum.
12, The Left Diaphragmatic Portion of the Pleura Costalis. 13, Left Pleura Costalis.
14, 14, The Middle Space between the Pleura), known as the Anterior Mediastinum.
15, The Pericardium. IC, Fibrous Partition over which the Pleurae are reflected. 17
Tlie Tracliea. IS, Thyroid Gland. 19, Anterior Portion of the Thyroid Cartilage. 20
Primitive Carotid Artery. 21, Subclavian Vein. 22, Internal Jugular Vein. 23, Bra*
chio-Cephalic Vein. 24, Abdominal Aorta. 25, Xiphoid Cartilage.

436. What are the Lungs 1

AND PHYSIOLOGY.

247

are of a conical shape, the apex pointing upwards, the hase
resting on the Diaphragm, of a pinkish gray color, frequentlj
dotted with black spots, and divided by a deep fissure into
two lobes. The right lung is shorter in its long diameter
than the left, on account of the liver which raises the right
side of the diaphragm higher than the left. The right lung
is subdivided again, so that it is really made up of three lobes
instead of two. It has also a larger capacity than the left,
since the position of the heart, considerably upon the left
side of the median line of the body, occupies a portion of the
left thorax. Each of the lungs ordinarily contains a pint of
blood.

437. Lobules of tlie Lungs. — A closer examination of the
lungs shows them to be made up of small bodies called Lung-
lets. These are from 4Vth to y 2 th of an inch in diameter, and
of a conical or pyramidal shape. They are much more clearly
defined in small children than in adults. Fig. 249, by the

Fig. 249.

f cl Jt

A Lunglet with a Section of a Bronchial Tube, o, Bronchus, 5 and c, Vessels <jf
Bronchial Lining Membrane. <f, d, e, e. Spaces between contiguous Lobules, contain-
ing the Terminal Pulmonary Arteries and V«ins, supplying the Cjipillarj Plexus (^ /,)
to the Meshes of which the air gains access "by the Lobular Passages. - - . . -•

Give their shape, color and division. What are the lobes of the lungs? Which is the
largest l.ung, and why the difference ? 437. How are the lungs made up? At what pe-
riod of life can the lunglets be best seen ?

11*

248 HITCHCOCK'S ANATOMY

hexagonal figure surrounding the bronchial tube, shows a
section of a lunglet, or lobule of the lung.

438. Tlic Pleura.— Pleurisy.— Root of the Lungs.— The
lungs are immediately invested with a serous membrane called
the Pleura, which is also the inner lining membrane of the
walls of the chest : so that when the lungs are fully inflated,
these two surfaces are brought in contact, and in the act of
respiration move slightly upon each other. And if any por-
tion of these membranes becomes inflamed, the disease results
which is known as Pleurisy. In the acute or early stage of
this disease, if a long breath be drawn, intense pain is felt at
the lower portion of the lung. This is owing to the friction
of these inflamed membranes one upon the other, and the
reason why the pain is severest in the lower part of the lung,
is that this part of the lung moves over the largest space in
breathing. The vessels for supplying blood, emptying it
and nourishing the lungs, as well as the air-vessels, nerves
and lymphatics, are all collected together in one bundle at
the inner side of these organs, and are collectively called the
Root of the Lungs.

439. The Air Passages. — The vessels which are especially
designed for the purpose of conveying air into the lungs are
the Larynx, from the Greek meaning a whistle, since sound
is made in it — the Trachea, meaning rough, as is its struc-
ture— the Bronchia, meaning the windpipe, (Fig. 250, p.
249), and the intercellular passages which terminate in the
air-cells. (Fig. 252, p. 250.)

440. The Larynx. — The Larynx is a conical cartilaginous
tube from one to two inches in diameter, opening upwards into
the Pharynx, and terminating below in the Trachea. (See
Organs of Voice.)

441. The Trachea.— The Trachea is a cartilaginous tube

438. What are the lungs covered with, and what Is the chest lined with? What is
Pleurisy? What Is meant by the root of the lung? 439. Give the names of the dif-
foront parts of the air-passages. 440t Describe the Larynx.

AND PHYSIOLOGY

Fig. 250.

24&

The Larynx, Trachea, and Bronchia, deprived of their Fibrous Covering, and with th«
outline of the Lungs. 1, 1, Outline of the Upper Lobes of the Lnngs. 2, Outline of the
the Middle Lobe of the Eight Lung. 3, 3, Outline of the Inferior Lobes of both Lungs.
4, Outline of the Ninth Dorsal Vertebra, showing its relation to the Lungs and the Ver-
tebral Column. 5, Thyroid Cartilage. 6, Cricoid Cartilage. 7, Trachea. 8, Eight
Bronchus. 9, Left Bronchus. 10, Crico-Thyroid Ligament. 11, 12, Elngs of the Tra-
chea. 13, First Eing of the Trachea. 14, Last Eing of the Trachea, which is Corset-
shaped. 15, 16, A complete Bronchial Cartilaginous Eing. 17, One which is Bifurcated.
18, Double Bifurcated Bronchial Eings. 19, 19, Smaller Bronchial Eings. 23, Depres-
sions for the Course of the large Blood- Vessels.

about one inch in diameter, made up of from fifteen to twenty
cartilaginous rings, commencing at a point nearly opposite
the fifth cervical vertebra, and extending as low as the second
dorsal, or top of the sternum, -where it divides into two bron-
chi extending to each lung. These segments of the trachea
are not perfect rings, since they complete only about .five sixths

441. Ho-w is the trachea made up? "Where does it divide into tho twobroaclii ? Ar©
the segments of the trachea, petlect rings ?

250

HITCHCOCK'S axato:my
Fig. 251.

Capillaries of the Human Lung.

of a circle, the remaining sixth consisting of smooth or invol-
untary muscular fiber.

442. The Bronchi. — Intercellular Passages.— Csecal
Air-Celh. Their Number. — As soon as the Bronchi fairlr

Fia. 252.

A Magnified View of a Section of the Lnnp, showing the Arrangement of some of
tbo Lobules, the Cominnnication of the Air-Cells in one Lobule and their Separation-
from those of the adjoining- Lobule. The Ramifications of the Blood- Vessels in the
Texture of the Lung and their Course throuirh the Air-Cells are also seen. 1, 1,
Branches of tho Pulmuaary Veins. 2, 2. Branches of the Pulmonary Artery.

AND PHYSIOLOGY

251

enter the lungs, thej immecliatelj divide and subdivide, until
they have diminished to a diameter about one fiftieth of an
inch, and some of them are within one eighth of an inch of
the outside of the lung. After this they are changed in their
structure, and become channels hollowed out in the cellular
tissue of the lung, and are called Intercellular Passages.
These terminate in minute
cells, called Csecal Air-Cells.
These cells have an average
diameter of yl^th of an inch,
and accumulate around each
terminal bronchus to the num-
ber of 17,790, making a total
in the lungs of 600,000,000,
which, if spread out, would
make an area of cell surface
of 132 square feet; Dalton
says 1,400 square feet.

443. Composition of the
Air-Tubes. Their Mucous
and Pleural Surfaces. —
These air-tubes just described
are essentially composed of
cartilage and fibro-cartilage,
and lined throughout with
mucous membrane. Hence
we see that this membrane,
though situated nearest the
center of the body, lines the
outside of the lungs, while
the Pleura, although nearer

the surface of the body, lines Small Bronchial Tube laid open.

Longitudinal Section of the Termina-
tion of a Bronchus. 1, Bronchus. 2, Cae.
cal Air-Cell. 8, Orifice of the same.

Fig. 254.

442. What are the bronchial tubes subdivided into ? How large are the caecal air-cellsT
IIow many around each terminal bronchus ? What is their aggregate number ? What
13 the area of cell surface in the lungs? 443. What is the composition of the air-tubes?
Which, is really tlieinside and •which the outside of tho lungs ?.

252 HITCHCOCK'S ANATOMY

the interior of the lungs. This apparent contradiction of
terms arises from considering that portion of the body as ex-
ternal which is in contact with the air, in the same manner as
the intestines ; the anatomically external surface being phys-
iologically the internal surface.

444. The Substance of the Lungs —The substance of the
lungs is entirely made up of arteries, veins, lymphatics, and
bronchial tubes, connected by areolar tissue. And when in-
flammation takes place in this substance, the disease is known
as pneumonia, or lung fever.

445. The Essential Muscle of Respiration — Process of
Brefithing— The Rest Gained by the Respiratory Muscles-
— The muscle which performs the most essential part of
breathing is the diaphragm. This by its contraction produces
inspiration, but does not directly produce expiration. Breath-
ing is performed as follows. The cavity of the chest is va-
riable in size ; made so by the movement of the diaphragm
Upwards and downwards. For as the sides and upper portion
of the chest are unyielding walls, if the diaphragm be de-
pressed the cavity of the chest is enlarged, a partial vacuum
is produced, and the air rushes in to supply the vacancy.
This is inspiration, and is purely an active muscular effort.
Expiration, however, is quite the reverse, being wholly a pas-
sive exercise. For when the lungs are filled, the contents of
the abdomen are depressed by the descending diaphragm and
the ribs are elevated, both of which parts offer resistance to
the inhaling force. Consequently, when the diaphragm and
the other respiratory muscles are relaxed, several muscles of
the back, abdomen, and chest, by their elastic tonicity, force
air again out of the mouth, which completes the process of
expiration without expending any nervous energy, and at the
same time gives Test to the muscles employed in breathing.
Hence the muscles of respiration are not ail the time in ac-

444. What is tho substance of the lung composed of? Define pneumonia. 445. What
is the principal muscle of respiration? Describe the mechanism of brcathins- Wliicli
act is active and ■wbicli is passive ? When do tlie respiratory inu&cles rest ?

AND PHYSIOLOGY. 253

tion, but as the period occupied by expiration is longer than
that of inspiration, consequently they rest during a longer
time than they are in action.

FUNCTIONS OF THE LUNGS.

446. The First Object of Breathing. — The immediate
object of breathing is to bring air into the lungs and carry
it out again after it has performed its office ; and the function
of the lungs is to expose as large a surface of blood as possible
to the air inhaled. The ultimate objects of this arrangement
are to remove waste products from the body, which exist in
the form of carbonic acid and water, and also to generate the
animal heat necessary. A third, but by no means an incon-
siderable value of this function, is to convert the gluten of
vegetable food into fibrin.

447. Another Use of Breathing, Purifying the Blood
— Endosmose and Exosmose.— The impurities of the blood
— carbonic acid and water — are exchanged for the oxygen of
the atmosphere. This is not effected by actual contact of
blood and air, but through an intervening membrane, the
wall of the air-cells. It is a remarkable property of mem-
branes, both animal and vegetable, called Imbibition, or En-
dosmose and Exosmose, that allows fluids and gases to pass
through them in opposite directions at the same time.
Through the membrane of the lungs, the carbonic acid, which
has more affinity with pure air than for the blood, passes out-
wards, while the pure air, containing oxygen, has an affinity
for the blood, and passes inwards.

448. Amount of Air Used in Breathing— Causes of its
Variation— Capacity of the Chest.— The average amount
ef air which passes in and otit of the lungs at each inspiration

446. What is the object of breathing, and •what is the function of the liings ? What
three processe.- are accomplished by this process? 447. How does breathing purify tha
blood? Describe the process of imbibition. -

254 HITCHCOCK'S ANATOMY

and expiration is about twenty cubic inches, and the amount
passed through them in twenty-four hours about 360 cubic
feet, or, as others . estimate it, from 3,000 to 5,000 gallons
every day. This varies greatly. In the first place, the lower
the temperature the greater the amount of animal heat to be
generated, and consequently the greater the quantity of air
to be consumed. Also a person laboring in the open air
breathes more deeply than one confined to the house. Again,
the capacity of the lungs modifies the quantity of air inhaled.
And this capacity depends more upon the height of the indi-
vidual than any other physical feature. From a series of
5,000 observations made by Dr. Hutchinson, the following
principle is deduced. '' For every inch of stature from
five to six feet, eight additional cubic inches of air are given
out at a forced expiration after a full inspiration." That is,
if a person five feet and six inches in height can expire 422
cubic inches, a person five feet and seven inches can expire
430 cubic inches.

449. Effect of Corpulence on Capacity of lungs.—
Another fact of importance is deduced by the same experi-
menter— that if a person exceed the average weight on ac-
count of corpulence, the capacity of the lungs decreases in a
marked ratio, as is stated in these words : '' When the man
exceeds the average weight (at each height) by 7 per cent, the
vital capacity decreases one cubic inch per pound for the next
thirty-five pounds above that weight."

450. Function of the Red Corpuscles.— The red cor-
puscles of the blood seem to be the carriers of oxygen from
the lungs to the various parts of the body. The prominent
reason for this belief is that the serum and salts of the blood
have but a very slight power of absorbing oxygen, while the
discs condense this gas at once.

448. How miicli air is used in each act of inspiration, and liow much each day ? IIow
does tempei-ature and exposure to the open air affect the amount respired ?- Upon what
does the capacity of the lungs depend ? Give the law and its example. 449. IIow does
corpulence affect the capacity of the chest? Give the formula. 450. What is the prob-
able function of the red corpuscles of the blood ? ' '

AND PHYSIOLOGY. 25b

451. Inspirations compared witli Pulsations — (Quan-
tity of Watery Yapor Given off in Twenty-four Hours —
Amount of Carbonie Acid Exhaled— The Amount of Solid
Carbon given off. — If we compare the number of inspira-
tions in a minute with the pulsations of the heart, we shall
find the proportion of the former to the latter is as one to
four or five in the human adult. Every fifth breath is usually
deeper than the preceding four, and the time occupied by
each respiratory act is about three and a half seconds ; and
all the blood in the body (when in vigorous exercise) probably
is exposed to the air in the lungs every two minutes.

The quantity of watery vapor which is ordinarily exhaled
from the lungs in twenty-four hours ranges from sixteen to
twenty ounces. The amount of carbonic acid, however, varies
much more, being from one to three pounds in twenty-four
hours, and the causes of variation are temperature, age, sex,
state of health or disease, development of the body, muscular
exertion or repose, sleep or watchfulness, and period of the
day. " This gas (carbonic acid) contains in every 100 pounds
28 pounds of carbon (charcoal) and 72 pounds of oxygen
(gas). Hence the weight of carbon which escapes in this
form from the lungs of a full-grown man varies from five to
fifteen ounces in twenty- four hours."

452. Respiration as a Source of Animal Heat. — The
value of the function of breathing as a means of producing
animal heat, will be considered under the organs for produc-
ing heat.

453. Changes in the Food effected by Respiration. —
A third object of breathing is to effect such changes in the
food that it can be directly converted into the different tissues
of the body. Hence the oxygen of the air is a part of the
food that we live upon. For although the gluten which is so

451. What is the relative number of inspirations and pulsations of the heart ? Wliat
length of time is occupied in breathing? What quantity of vapor of water is exhaled in
twenty-four hours, and what amount of carbonic acid? How is this amount modified ?
What weight of carbon or charcoal is given out of the body by the lungs everyday?
453. What effect has the oxygen of the air upon the glutinous portion of our food ?

256 HITCHCOCK'S ANATOMY

largely contained in vegetable food very closely resembles
fibrin (which is the form that the nutrient portion of the food
must be in before it can nourish the greater part of the body,
and especially the muscles), still chemical analysis shows that
the gluten must receive another equivalent of oxygen before
it is fitted to reproduce the different tissues of the body. And
the only way in which this oxygen can be given to the body
is either through the lungs or skin.

454. Amount of Air which the Lungs can Contain.—
The amount of air which the lungs actually do contain is by
no means the amount that should be actually supplied to them.
Por the air which surrounds the body is very rarely indeed
perfectly pure, but is contaminated with the previously ex-
haled breath, on account of the law of difiusion of gases,
which is, that when two gases are brought into contact they
immediately commingle with each other. Experiment shows
that between 350 and 400 cubic feet of air are actually ex-
haled during the twenty-four hours ; but experience shows
that the least quantity which should be allowed for dwelling-
houses, shops, and school-houses, should be 800 feet in order
to furnish a sufficient supply of oxygen.

CALORIFIC GEaANS.

455. fleat-producing Organs — Theory of Animal Heat.
— The organs which produce animal heat are essentially those
employed in the act of breathing and the circulation of the
blood, and consequently already explained, but the actual
in3thod by which it is produced has for a long time perplexed
physiologists. The theory which now is most readily accepted
makes the function to be a chemico-vital one, or a chemical

What is that element which principally nourishes the muscles ? 454, What is the law
of diffusion of gases, and what modifying influence does this have on the hygiene of res-
piration ? How many cubic feet of air should be allowed to every in-door laborer or
student? 455. What are the heat-producing organs? What is at present the most
readily accepted theory of animal heat ?

AKD PHYSIOLOGY. 25*1

change (oxydization) dependent upon vital energy, being
nearly analogous to the burning of a candle or the combus-
tion of wood and coal in the stove.

456. Process of Producing Animal Heat.— As the oxy-
gen in the inspired air enters the lungs and is brought into
contact with the blood through the wall of the air-cells, the
carbon of the venous blood unites with it, forming carbonic
acid, and heat is generated. This is precisely the same thing
that takes place in the furnace, where the air enters through
the draft supplying the oxygen, and the coal furnishes the
carbon, the result of the union being heat. But it is not in
the lungs alone that this heat is generated : for we have al-
ready seen that the blood is highly charged with oxygen as it
passes through the arteries to the various organs of the body.
And as it passes through the capillaries in every part of the
system, it there receives an equivalent of carbon, the waste
of the system producing carbonic acid, in which operation
heat is given off. Hence we see that heat is generated not
only in the lungs but in every part of the body, and that it
is incessantly being produced, which is a reason why the ex-
tremities of the body are constantly kept at their proper tem-
perature ; for if all the heat were to be generated in the lungs,
very frequently the blood would become chilled in its passage
to the extreme capillaries. We also see that forced respira-
tion has the same effect as increasing the draft of air into
the furnace, and that the fuel of the human system is sup-
plied by means of the food placed in the stomach.

457. Temperature of Human Body.— The temperature of
the human system is 98° F., and this it is invariably found to
be in all climates and seasons when the individual is in pos-
session of perfect health. So that in most climates the tem-
perature of the body is above that of the surrounding atmos-

456. Describe the process. Is all the heat of the body generated in the lungs ? Where
in the body is it wo^ generated ? What is the fuel of the body? Where is the draft?
457. What is the temperature of the human body ? How is the heat of the body com-
pared with that of nearly all climates ?

258 HITCHCOCK'S ANATOMY

phere, and we are constantly giving off heat to the air which
envelops us.

458. Manner in which the Body is maintained at its
uniform Temperature. — The manner in which the body is
kept at the uniform temperature of 98°, is a subject of deep
interest. It is partly accomplished by radiation, since the
body is ordinarily warmer than the air about it, and also
partly by inhaling the cool air into the air passages. It is a
well-known principle in chemistry, that, when any substance
passes from a more solid to a less solid condition, as from
solid to liquid, or liquid to a gas, heat is absorbed, or, in more
common language, cold is made sensible. This is seen in the
application of water, alcohol, or ether, to the skin, when a
sensation of cold is felt, which is owing to the fact that the
substance applied is passing from the form of a liquid to
that of a vapor. Now the same thing takes place when the
perspiration is allowed to evaporate from the surface of the
body. The increased flow of blood, as brought about by the
exercise, or the high temperature of the surrounding at-
mosphere, stimulates the vessels of the skin to more energetic
action, and sensible perspiration is poured out upon the sur-
face of the body. This, however, is now in contact with the
currents of air always present about the body, and it is readily
thrown out into a state of vapor, and in accordance with the
chemical principle just stated, heat is absorbed from the body
producing its uniform temperature.

458a. It should be mentioned here, that of late many
experiments have been carried on which seem to show us
that the above-mentioned theory of animal heat can not be
fully adopted. For it is well known that many chemical
combinations besides those of mere oxydation or "burning"
produce heat; and many of these processes are constantly
taking place in the body. But all the facts hitherto ad-

458. How is the body kept at its uniform temperature? What chemical principle
Illustrates this view ? 45Sa. Give the result of recent experiments.

A^s^D PIIYSIOLOGT. 2o9

vanced do not by any means entirely overthrow the old theo-
ry. They show us that the theory of combustion does not
cover the whole ground, but that other causes, as well as
oxydation produce animal heat. And we propose the idea
that animal heat, like digestion, is a chemico-vital process,
that is, a process under the immediate influence of chemical
changes, but entirely under the control of the vital principle,
since animal heat can not be maintained after death.

ORGANS OF THE VOICE.

DEFINITIONS AND DESCRIPTIONS.

459. The Larynx; its
Cartilages. — The Larynx in
all animals is the essential or-
gan for the production of the
voice. It has also very much
the same structure in every
animal which has the power of
expressing its feelings by the
voice. A cartilaginous tube,
imperfectly conical, the base
directed upwards, made up
of distinct portions or seg-
ments slightly movable upon
one another, and with a cer-
tain portion of the channel
lengthened into a narrow and
elongated opening, constitutes
a larynx. In man this organ
is made up of seven distinct
portions or cartilages, two
Arytenoid (pitcher-shaped),

Fig. 255.

A Lateral View of the Larynx. 1, Os
Hyoides. 2, Thyreo-Hyoid Ligaments.

3, Cornu Majiis of the Thyroid Cartilage.

4, Its Angle and Side. 5, Cornu Minus.
6, Lateral Portion of the Cricoid Carti-
lage. 7, Eings of the Trachea.

260

HITCHCOCK'S ANATOMY

two Cuneiform (wedge-shaped), one Cricoid (ring-like), one
Thjroid (shield-like,) and one Epiglottis (cover to the Glottis).
These together form the small prominent portion of the neck
known as Adam's apple.

460. Thyroid Cartilage.— Arytenoid Cartilages.— Gu-
neiform Cartilages.— Cricoid Cartilage.— Vocal Cords.—
Ventricle of the Larynx.— Mnscles of the Larynx.— Tho
Thyroid Cartilage is so arranged as to form a framework for
the movable portions of the organs of the voice, and this is
the principal cartilage that forms the Adam's apple. The
Arytenoid Cartilages can be moved by the small muscles of

Fig. 256.

Fig. 25T.

A Front View of the Thyroid Carti-
lage. 1, Left Half of the Cartilage. 2,
Anterior projecting Angle. 3, Superior
Margin. 4, Its Notch. 5, Inferior Margin.
6, G, Cornua Majora. 7, 7, Cornua Minora.

A Posterior View of the Left Arytenoid
Cartilage. 1, Its Posterior Face. 2, The
Summit. 3, The Base and Cavity for
Articulating with the Cricoid Cartilage.
4, Its External Angle. 5, Its Internal
Angle.

the larynx. The object of this movement is to relax or
tighten the vocal cords, so that the different pitch and quality
of voice may be perfected. The Cuneiform Cartilages are
about half an inch in length, and enlarged at each extremity.
These are sometimes wantinoj. The Cricoid Cartilaore is of a
ring-like appearance, and resting directly upon the rings of

459. AVhat i3 the essential organ of voice in all animals? Give the anatomy of the
larynx. Name the seven curtilages. 460. Describe the thyroid and arytenoid cartilages.
Describe the cuneiform and cricoid cartilages.

AND PHYSIOLOGY

261

the trachea, being of a little longer diameter than the trachea.
The Epiglottis is the most movable of all the vocal cartilages.-

Fig. 258.

A Front View of the Cricoid Cartilage.
1, Its Internal Face. 2, The Cavity of
the Larynx as formed by this Cartilage.
8, Its Interior Surface. 4, The little Head
or Convexity for Articulating with the
Arytenoids. 5, The Surface of the Su-
perior Edge for the Attachment of the
Lateral Crico- Arytenoid Muscles.

It in shape resembles a cord-
ate or heart-shaped leaf, at-
tached by its apex to the up-
per edge of the glottis, and
has a wide range of motion,
in order to completely close
np the passage into the lungs,
cr leave a free communica-
tion between them and the
air. It also aids in deaden-
ing sounds, as it is suddenly
brought down upon the glot-
tis. All these cartilages very

A Lateral View of the Epiglottis Carti-
lage. 1, Anterior or Convex Surface. 2,
Posterior or Concave Surface. 3, Superior
Margin. 4, Inferior Margin or Pedicle.
5, Its Sides. The Openings of the Muci-
parous Ducts are also shown.

A Posterior View of the Articulations of the Cartilages of the Larynx. 1, Posterior
Face of the Epiglottis. 2, Appendices of the Os Ilyoides. 3, Its Cornua. 4, Lateral
Thyreo-IIyoid Ligaments. 5, Posterior Face of the Thyroid Cartilage. 6, Arytenoid
Cartilages. 7, Cricoid Cartilage. 8, Crico-Arytenoid Articulation. 9, Posterior Crico-
Thyroid Ligament. 10, Cornu Minus of the Thyroid Cartilage. 11, Anterior Crico-
Thyroid Ligament. 12, Ligamentous Portijn of the first Pwing of the Trachea,

262

HITCHCOCK'S A N A T O 51 Y

frequently become censiderablj ossified in males in ad-
vanced age.

The Yocal Cords or ligaments are folds of white fibrous tis-
sue, covered by mucous membrane, and are made to vibrate
•when the air is forced over them. Hence ulceration, or any

Fig. 262.

A View of the Larynx from above,
showing the Thyreo- Arytenoid or Vocal
Ligaments. 1, Superior Edge of the La-
rynx. 2, Its Anterior Face. 8, Cornua
Majores of the Thyroid Cartilage. 4, Pos-
terior Face of the Cricoid Cartilage. 5, 5,
Arytenoid Cartilages. 6, 6, Thyreo-Ai'V-
tcnoid Ligaments. 7, Their Origin within
the Angle oi the Thyroid Cartilage. 8,
Their Terminations at the Base of the
Arytenoid Cartilages. 9, The Glottis. 10,
Anterior Part of the Inferior Surface of
the Cricoid Cartilage.

Muscles of Human Larynx. G. E. ff.
Thyroid Cartilage, r. io. X. w. Cricoid.
-V. F. Arytenoid. T. V. Vocal Ligaments.
A^, X. V. K. /. and N. I. Muscles of La-
rynx.

alteration in the structure of these cords, will produce hoarse-
ness, a loss of intonation — a whispering — or some change in
the quality of the voice. The cords just mentioned are not,
however, the only ones that exist in the larynx, for these are
the upper ones, while another pair called the inferior cords,
exist below the others, leaving a cavity known as the ventricle
of the larynx, (Fig. 263, p. 263), which seems essential to
the proper production of sound : although there is nothing
analogous to it in the ordinary musical instruments. The
muscles connected with the larynx are eight : five of them

What is the epiglottis ? Of what are the vocal cords composed ? What Is the ven-
tnclc of the larynx? How many muscles belong to the larynx?

AND PHYSIO LOGY

Fia. 263.

263

Cartilages of Larynx and Epiglottis, a. Arytenoid. &. Its Superior Cornu. c. In-
ferior Cornu. d. Cricoid. /. Perforation of Epiglottis, i. Upper Part of Thyroid.
t. Trachea, h. Tubercle.

pass between the different cartilages, and are of use in regu-
lating the size of the glottis and the tension of the vocal cords,
while the three remaining go from the epiglottis to the dif-
ferent parts of the larynx, solely for the purpose of moving
this valve to aid in articulation and closure of this passage to
the lungs.

Which movo the cartilages, and which are dlatributed mainly t» the epiglottis ?

13

264 iiiTcncocK's anatomy

FUNCTIONS or THE LARYNX.

461. Similarity of the Larynx to a Reed Instrument. —
The larynx, as an organ of sound, very much resembles a
reed instrument, or the reed pipes in an organ. For we
have the reed, or rather the reeds, in the vocal cords, and the
column of air in the pharynx and mouth. This, however,
differs from Xaq proper reed instrument by the vibration of
free edges of the reed, and also by the power of tightening or
relaxing the cords to produce different pitches of tone ; for in
the hautboy, bassoon, and similar instruments, the tone is
regulated by the length of the vibrating column of air, which
is controlled by the keys and finger-holes.

462. Use of the Cartilages.— The arrangement of the
cartilages of the larynx is such as to give form and stability
to the organ, and at the same time a firm attachment to the
vocal cords, muscles, and ligaments. In male adults these
are much larger than in females, since the voice of the former
is heavier and of a much lower tone than that of the latter,
requiring greater length of vocal cord, and consequently
firmer points of attachment.

463. Organs Essential for tnc Production of mere
So unci .—The vocal cords, together with the diaphragm, ab-
dominal muscles, and lungs, are all the organs which are
necessary for the production of sound. But the quality of
sound and articulation are produced and modified very essen-
tially by other parts of the body.

464. Use of the Cavity in the Frontal Bone.— The si-
nus, or cavity in the frontal bone which communicates with
the pharynx, is a very important member of the vocal organs,
as it imparts resonance to the voice in the same manner as the

4G1. What kind of instrument docs the larynx resemble? What correspond to the
reeds? 462. Of wlic.t nso are the cartilages? Are the vocal cords longest in man or
^voman ? What is the result of it? 463. What organs of the body are necessary for tlie
l;roduction o f soimd ? 464. Of ^vbat u: e is the cavity in the frontal Lone ?

AND PHYSIOLOGY. 265

hollo-w portion of the violin and violincello, or the long tube of
brass instruments, gives the proper tone to these instruments.
The want of such a cavity for the perfection of the human
voice is well appreciated, when a person is suffering with a
severe cold in the head, as it is termed. In this case the
voice is of an extremely nasal character, because the passage
to the frontal sinus is closed up by a thickening of the lining
membrane, which prevents a resonance of the tones made in
the larynx.

465. Function of the Nostrils in the Voice. — An open
passage through the nostrils is also very important for the
production of perfect tones of the voice. For when this is ob-
structed in any way, the head or nasal tone is invariably pro-
duced.

466. Function of the Tongue in the Making of Ar-
ticulate Sound — Not Absolutely Essential.— The tongue
is the chief organ of articulation, and in connection with
the lips and teeth, the tones made in the glottis are either
lengthened or shortened, and otherwise modified to form the
different letters. If either of these organs is deficient in sub-
stance or function, the articulate sounds are imperfect ; as,
for instance, the letters T, D, L, F, and S, which require a
full development of all the parts for their perfect enunciation.
It is, however, stated as a fact, that some people have been
known to articulate words with distinctness after the tongue
was removed by a gun-shot wound.

UYaiENIC INFERENCES.

46 T. — 1. From the size of the lungs we see that they are
organs of great importance in the system.

468. — 2. Liability of the Lungs to Disease.— On ac-
count of their delicate structure and constant use, they are

What produces th(?-talking through the nose, as it is termed? 465. ITow do the nos-
trils affect the voice ? 466. What use lias the tongue in speech ? Also the teeth and
lips? Is the tongue always absolutely essential? 467. What does the great size of the
lungs show us ?

266 HITCHCOCK'S ANATOMY

liable to disease, and consequently need especial care to keep
them in health.

469. — 3. Action of the Lungs Essential for tlieir
Ilealtli. — One important item to secure the health of these
organs, is to keep every part of them in action. Hence pres-
sure of clothing, or any thing else that prevents the complete
filling of the lungs by breathing, is quite sure to induce dis-
ease. For if but a very few of the millions of air-cells con-
tained in the lungs are allowed to lie inactive or useless, na-
ture will attempt their removal by means of the lymphatics,
and this removal is often the commencement of fatal disease.
Therefore it is a good practice for every one, and especially
sedentary persons, several times each day to throw back and
downwards the shoulders, and slowly fill the lungs to their
utmost capacity, and then permit the air to escape slowly, be-
cause in this way every cell in the lungs will be used.

470. — 4. Pure Air is Essential to Healthy Lungs —
Life Depends on Breathing Pure Air/^ — All mechanical
and chemical impurities of the air inhaled induce and ag-
gravate disease. Indeed, the most important hygienic rule
for the lungs is to breathe pure air. Mechanical impurities,
such as dust and vapors, are eminently injurious, but not so
much so as the chemical impurity, carbonic acid, which comes
from the exhalations of men and animals, and the burning of

* Black IIolw of Calcutta. — One of the most awful instances of suffocation on rec-
ord, is connected with what is known as the Black Hole of Calcutta. When Calcutta
was taken by the Indian forces, the British garrison, numbering 146 men, were confined
as prisoners of war in the dungeon of the fortress, a room only eighteen feet square, and
Intended only for confinement of two or three men. This dungeon had only two small
windows, both upon one side of the building, in front of which was a verandah that aided
greatly in impeding whatever slight circulation of air there might be. Besides the great
heat of a July night, on which this occurred, conflagrations Avere raging near the fort
Avhich greatly increased the heat. Very soon after the men were confined, the suffering
became intolerable, and the dungeon Avas a scene not only of the intensest anguish, but
of frightful delirium of most of the inmates. By eleven o'clock the men began to dio
very rapidly, and owing to the intense heat and overpowering stench caused by these
exertions of the frantic soldiers, In the morning at six o'clock, when the doors wera
opened, but twenty-three were aJive, who were either stupefied or raving.

468. What does their delicate structure show ns? 469. What is said of the necessity
of action for the lungs ? What habit is of great service, and why is it ? 470. ITow do im-
purities of the air affect the lungs? What kind of impurities are the most injurious?
What la one of the principal sources of disease In civilized society ?

AND PHYSIOLOGY. 267

all combustible substances. And it is safe to saj, that the
greater the care we take to Ventilate our rooms, and in every
way to breathe pure air, the longer shall we live and with
the least amount of pain and disease. Breathing impure air
is one of the greatest natural evils to which civilized society-
is subject, and destroys more lives than almost any other.

471. — 5. We need Pure Air by Night as well as by
Day. — Hence we see that the lungs need pure air all the time,
by night as well as by day — in the sitting-room, the eating-
room, and the bed-chamber, the school-house, the meeting-
house, rail-car, and steamboat, if we would do our utmost to
ward off disease and death.

472. — 6. Capacity of the Lungs Affected by Posture. —
The capacity of the chest is greatly influenced by our posi-
tion in sitting or standing, and the amount of use to which
it is subject. If the shoulders are thrown forward or the
body is bent in the same way, the lungs are compressed, and
can not be filled to their full capacity. Hence special pains
should be taken to maintain the body in an erect posture, and
to keep the chest thrown forward.

473. — 7. Pure Air is often a Medicine- In most diseases
the breathing of pure air is important for restoration to per-
fect health, since there are often some impurities in the blood
or system which are removed mainly by pure air. So that
the rule of supplying pure and warm air to the sick room
should be rigidly observed.

474. — 8. Warm and Moist Air the Best for a Healthy
Person. — The air best adapted for breathing should contain
but a small amount of moisture, nor should it be perfectly
dry, especially that which comes from intensely heated iron
surfaces. Cold and damp air is apt to bring on irritation of
the mucous membrane, producing coughs and colds.

475. — 9. Capacity of the Lungs may be Increased. —

471. When and where do we need pure air ? 472. How is the capacity of the lungs
modified? What of the necessity of an erect posture in sitting or standing? 473. Why is
pure air so important in sickness? 474. Wliat in the best quality of air for breathing?

268 HITCHCOCK'S ANATOMY

The langs, if compressed by disease or improper clothing, and
even in many cases of so-called perfect health and soundness,
can be very much enlarged in their capacity. This can be
done by loud reading, or by the simple act of filling the lungs
■with air to their utmost capacity several times each day, after
the manner mentioned under inference 3d. If this healthy
habit be kept up for a few years even by some considerable
effort, nature will at length take up the habit, and we shall
ultimately be found involuntarily filling the lungs with pure
air, and thus fix upon ourselves a hygienic habit of great im-
portance in preserving health, and of great value in repelling
disease.

476. — 10. Colds and Coughs— Treatment— Sympathy
hetween the Different Parts of the Mucous Membrane. —
Colds and ordinary coughs are affections of the mucous mem-
brane, and generally only of the lungs, pharynx, and nostrils
and air passages leading to the lungs. They are often pro-
duced by obstructions in the vessels of the skin, and hence a
great relief in many instances for a cold, and often a cure, is
to remove this obstruction by stimulating these vessels to
powerful action, as in sweating. This effect is produced by the
sympathy which exists between the skin and mucous mem-
brane, one often performing the function of the other for a
short time. The mucous membrane also has a remarkable
sympathy between its different parts ; and hence even the
portions which are unaffected by the cold should be kept as
quiet as possible, by taking, for instance, but little food into
the alimentary canal, and that of a liquid character, so that it
may be readily taken up by the absorbents of the stomach.

477. — 11. Injurious Effects of AVearing Shawls hy
Gentlemen. — From the fact that whatever compresses the
chest greatly tends to bring on diseases of the lungs, we in-

475. How can tlio size of tlie Inngs bo perceptibly increased ? 4T6. What are colds and
coninion couglis? How are they often induced ? What is their best treatment? What
is remarkable about the sympathy between the skin and the mucous membrane? 477.
How are shawls often injurious to th« lungs ?

AND PHYSIOLOGY. 269

fer that the wearing of shawls by gentlemen, inasmuch as it
requires a drawing forward of the shoulders to make them
thoroughly cover the body, compresses the lungs, and there-
fore is highly injurious. Moreover, it makes a person round-
shoulderedj and thus gives the appearance of premature old
age.

478.-12. The Neck to be Dressed lightly.— From
the many movements which are made by the larynx in speak-
ing, we infer that it is a matter of great importance that the
neck in health should be always loosely dressed. For tight
cravats and neckcloths are sure to obstruct the proper func-
tion of this organ, and bring on irritation, which may end in
bronchitis or consumption.

479. — 13. 1 Strong Voice Demands Vigorous Exer-
cise of all the Body. — We learn also that they who would
have the strongest and best developed voices for speaking and
singing should pay special attention to the general health, and
particularly to muscular exercise in the open air, because the
voice depends so much more upon the healthy condition of
the whole body than it does upon the healthy or unhealthy
condition of the larynx.

480. — 14. Great Aid in Speaking can be Acquired
by Enunciating the Simple Vowel Sounds.— Experience
shows that great aid can be given to those who would secure
pure and correct tones in speaking by slowly but distinctly
enunciating the simple vowel sounds of the English language.
This not only strengthens the organs, but it gives a proper
training to the laryngeal muscles, so that in the composi-
tion of vowels and consonants the muscles will contract to
their proper amount, and only to that.

47S. What clothing should be given to the neck ? What is one source of bronchitis?
479. How is the voice made and kept clear and strong ? 4S0. How can poor epeakeij
and readers make themselves superior ones ?

270 HITCHCOCK'S ANATOMY

COMPARATIVE PNEUMONOLOGY.

RESPIRATOKY ORGANS.

481. Trachea. — The Trachea in some animals, such as the
horse and cow, consists of complete rings, while in many ani-
mals they are only portions of rings, whose free extremities
are united hy membrane. In man these rings number from
seventeen to twenty, in the whale from seven to twelve, in
the carnivora from thirty to forty, and in some camels one
hundred and ten.

482. Bronchi. — The Bronchial Tubes are usually two in
number, but in the ruminants, the dolphins, and some other
mammals there are three. This third tube is always the
smallest, and passes to the right lung.

483. Lungs. — In the horse the lungs are undivided, but
in most quadrupeds the number of lobes is greater than in
man. In the marmot and hamster there are five in the right,
and three cr four in the left lung. In the musk deer the
right lung is nearly twice the size of the left. The terminal
air-cells of all these animals correspond in size very nearly
with those of man. The lungs are proportionally the largest
in the more powerful carnivora, and smallest in the weak
herbivora, and the red blood corpuscles are much more abund-
ant in the blood of the former than of the latter.

484. Respiration of Birds. Lunglets. — In Birds the
respiratory apparatus, like that of Insects, extends through a
large part of the body, (Fig. 264, p. 271), not only in tho
lungs proper, but through the channeled bones which are lined
with a membrane for purifying the blood. (Fig. 265, p. 271.)

4S1. How does the trachea in many of the loAvcr animals differ from that of man?
What is tho relative number of rings in each ? 4S2. What is said of the number of tho
principal bronchial tubes ? 4S3. What of the number of lobes in many quadrupeds? In
M-hat animals are the Inngs largest and in what ones weakest? 4S4. How is the respir-
atory apparatus of birds and insects alike?

AND PHYSIOL OGT

Fig. 264.

271

Trachea.

Pulmonary Vessels. .

Lung. ~...^
Broncliic Orifices. -

Bronchus laid open.

Bronchus laid open.

Lungs of a Bird.
Fig. 265.

Pulmonary Apparatus of a Pigeon, as seen on removing the Anterior Wall of the
Thorax, a. Trachea, h. Bronchi, c. Lungs, d. Apertures of Communication
with Air-Cells.

12*

272

HITCHCOCK'S ANATO

Large air-sacs are also contained in the abdomen, freelj com-
municating with the lungs, and acting as reservoirs for them.
A minute examination of the structure of these organs shows

Fig. 266.

Lunglet of a Fowl. A. Section passing in the direction of the Bronchus. B. Sec-
tion cutting it across.

Fig. 2Q1.

e

Lungs of Frog. a. Hyoid Apparatus.
I. Cartilaginous Ring. c. Lungs Proper.

that they are made up of lo-
bules or lunglets, each of
which has its own system of
vessels, and but little com-
munication with the other
lunglets.

485. Lungs of Reptiles.
— The Hiss of Serpents. —
Mechanism of Respira-
tion.— The Lungs of the
several orders of Reptiles are
for the most part capacious
sacs, the extent of surface in
which is but little increased
by smaller sacs or vessels
within them. In the Frog,

What appendages do they have wliich do not exist In quadrupeds f 435. What are the
lungs of reptiles?

-A VD PHTSIOLOGY

Pig. 268,

273

Lungs of Serpents, a. Trachea.
d. Pulmonary Artery.

b. Bronchi, c. Ki?ht Lun?,

Left Lun"

for example, the bronchi terminate in capacious cavities, upon
the sides of which are the pulmonary blood-vessels. In m my
serpents the pulmonary apparatus consists of a loug cylindrical
sac or lung upon the right side of the body, the correspQndin ^
one on the left side being merely rudimentary, l3 ^3en in Fig.
268. Serpents are capable of expiring and inhaling Iiirg3
quantities of air, which compensates for the want of a great
internal surface of lungs. And the peculiar hiss made by
them is simply a prolonged expiration of air from the lungs.

How is it in frogs and serpents? What makes the hiss of serjicnU ?

274

HITCHCOCK'S ANATOMY

Fig. 269. Fig. 270.

liUng of Turtle laid open.

Gills of Eel. A. Enlarged Portion.

In aquatic serpents the amount of air contained in the body
tends to make it buoyant, and at the same time supplies the
wants of the animal during a long immersion. In frogs and
many of the class reptilia the air is forced into the lungs bjr
a process similar to that of swallowing. Taken as a whole,
this order is remarkable for the feebleness of its respiratory
actions, and the length of time which the function can be sus-
pended without injury. The temperature in which the ani-
mal lives, however, greatly modifies the amount of air exhaled
and inhaled.

486. Gills of Fishes. — The Respiratory apparatus of
Fishes consists of Gills for procuring the air contained in
water. The Gills are fringes of minute bronchial tubes sus-
pended from cartilaginous and bony arches, that are situated

How do frogs inspire ? What efiect has the temperature upon the respiration in, this
class of animads? 4S6. What are the organs of reqtiration in fishes?- Describe the gill&

AND PHYSIOLOGY. 2'7.5

just behind the lower jaw. ''These are disposed, in most
fishes, in fringed laminae, which are set close together like
the barbs of a feather, and are attached on each side of
the throat in double rows, to the convex margins of four or
five long, bony, or cartilaginous arches, which are suspended
from the hjoidean arch."

487. Air-Bladder. — Another organ which perhaps claims
attention here, is the Air-Bladder. This is a small shut sac
— sometimes nearly subdivided into two or more sections by

Fig. 271.

Alr-Snc of Fisli (Carp), a. h. A Divided Form. c. d. A Tube connecting it with the
Eeophagus o.

a membranous division — which lies near the middle of the
back. In most cases it has no connection with any other or-
gan, but sometimes has an opening into the esophagus or
stomach. The uses for which it has been supposed to exist,
are to enable the fish to alter its specific gravity, and also to
aid in respiration in some manner. It has also been conjec-
tured that it aids the sense of hearing, since it is in direct
connection with the auditory apparatus. It is filled with
atmospheric air, with greatly varying proportions of oxygen
and nitrogen. Some fishes that leave the water occasionally
and crawl over the land, have a cavity in the side of the head
for water, which is in contact with a respiratory apparatus,
and thus the fish can live for some time out of its native ele-
ment.— Wyman.

487. Describe tlic air-bladder. What does it Eometimes communicate with ? Give its
probable uses. What is it filled with ?

276

HITCHCOCK'S ANATOM

488. Trachea of Insects.— Spiracles. — Mechanism of
Respiration.— Wisdom of this Arrangement.— The res-
piratory vessels of Insects are analogous to those of hirds
in that they extend through a large part of the body.

— A

Tracliea of 'Water-Scorpion, a. Head. h. First Pair of Legs. c. First Segment of
Thorax, d. Second Pair of wings, e. Second Pair of Legs. /. Tracheal Trunk, g. One
of the Stigmatae. A. Air-Sac.

The essential organs are Trachege or air-vessels, which open
upon the sides of the body, and freely communicate with one
another. Air sacs are found in the front parts of the body

4S3. What are the essential organs of respiration in insects? Whereabouts in the ani-
mal are the trachea found 7

AND niYSIOLOGT. 27T

of some iDsects, and the tracheae are very minute, ramifying
through the most delicate organs of the body, which plan
allows a rapid aeration of the blood, and greatly assists in
diminishing the specific gravity of the animal. The openings
upon the surface of the body are called Spiracles or Stigmata,
and are either oval or made in the shape of a slit, as is
seen in the adjoining cut. In the soft-skinned insects thej

Spiracle of Common Fly.

are surrounded by a ring of cartilage, to prevent their closing
by ordinary accidents or pressure, and all spiracles are pro-
tected by a kind of sieve or grating, made up of hairs ex-
tending from either side of the aperture, which keeps out
dust, that would otherwise enter with the air and stop the
passage. The interchange of air is eflfected by the enlarge-
ment and contraction of the abdomen. The rings, (or skele-
ton), which surround the abdomen, are seldom inflexible, but
are made up in one part of membrane, and the horn-like ends
are brought together by muscular contraction, by which
means expiration is effected. The enlargement or inspira-
tion is accomplished by the simple elasticity of the encasing
rings of the body, as well as of the trachea. Hence, full-
ness is the natural or passive state of the respiratory or-

What are the spiracles? How are they soraethnes protected? Give the mechanism
of respiration.

278 HITCHCOCK'S ANATOMY

gans, as was seen to be the case with birds. Still another
way in which respiration is effected, is by the sliding of one
ring inside the next one, like the joints of a hand telescope,
and their return by the elasticity of the tissues of the body.
And we can not fail to observe the beautiful design of the
Creator, when, though he furnished but a limited circulation
of fluid, yet fully compensated for it by introducing the air in
minute tubes to the very center of every tissue.

489. Crustaceans . — These animals breathe mostly by gills.
The Myriapods have proper tracheae, though with some respi-
ration is chiefly cutaneous, that is, directly through the skin.
The Arachnoid or Spider tribe sometimes have tracheae and
sometimes even lungs. The gills of the Crustaceans are situ-
ated in different parts of the body, more especially on the
feet.

490. Molluscs. — In the Acephala the blood before return-
ing to the heart passes through a bronchial organ or gill,
which opens and closes for the ingress and egress of water.
Some of the Cephalophora have gills ; others lungs, and others
a system for the circulation of water containing air, through
different parts of the body. The Cephalopoda all respire by
gills ; but they have also an aquiferous system.

49.1. Radiates. — ^'The simple exposure of the surface of
a jelly-fish or polyp to the action of the fluid around it is
sufficient to carry on all the changes which take place in its
simple kind of respiration." — Prof J. Wyman. Nearly all
the Radiates have such an aquiferous system. But many
of them have other organs for breathing. The Echinoderms
have gills; also sometimes their organs of prehension and
locomotion form a respiratory apparatus.

What instance of compensation is shown here ? 480. Do any crustaceans breathe by
gills ? 4?0. What is the breathing apparatus of molluscs ? 491. What is the respiratory
apparatus of radiates ?

AND PHYSIOLOGY. ' 2*IQ

THE SOUNDS PRODUCED BY ANIMALS.

492. Among vertebrates the production of vocal sounds is
confined to the air-breathing classes, since no fish or gilled
animal is able to make any sound by means of the special
organs which are provided for that purpose in other animals.

493. Laryngeal Pouches, or Sacs. — Nearly every mam-
mal can make some vocal sound, and the structure of the
larynx in all very closely resembles that of man. The howl-
ing apes present the most striking difference in these organs.
They have pouches, or laryngeal sacs as they are called,
connected with the larynx, which increase the loudness of
the voice simply by the resonance of the voice in these cavities.

494. The Two Larynges of Birds— The Trill of Birds.
— In birds the vocal organs are somewhat different from those
of man. There is in them a larynx, called the superior
larynx, at the summit of the trachea, which seems designed
mainly for the ingress and egress of air. But the vocal
sounds for which birds are so remarkable are made by what
is called the inferior larynx, which is situated at the lower
extremity of the trachea. This is most complex in birdst
which have the greatest powers of song. The two or three
lower rings of the trachea are usually consolidated into one^
and in the interior a cross bone runs from front to back which
has upon its upper edge a small membrane of a crescentic-
shape, which is so lax that it can freely vibrate when the air
is made to pass rapidly over it. This in its action, is anal-
ogous to the reed of the clarionet or melodeon. It is by the
vibration of this membrane that the peculiar trill of many
singing-birds is so beautifully executed. The intensity of the

492. What vertebrates alone can make vocal sounds ? 493. What is said of the struc-
ture of the larynx in all mammals ? What is the peculiarity among the howling apes ?
494. How many larynges have birds? Give the function of each. What peculiarity ia
the lower part of the trachea ?

280 HITCHCOCK'S ANATOMY

tune is greatly increased bj the construction of the trachea
and bronchi. "Birds whose voices have a very extensive
musical scale are able to shorten and lengthen their wind-
pipe considerably, and to that end have very thin wings and
large membranous interspaces."

495. Larynx of Reptiles. — Reptiles have an imperfect
kind of larnyx, which is located at the point where the trachea
opens into the pharynx. The only sounds which they can
make is the croak of the frog and hiss of the serpent, turtle,
or lizard. The common Erog has two vesicles or little bags
behind the angle of the mouth, which are much distended at
the beginning of summer and at pairing time, which accounts
for their loud croaking at these seasona.

496. Sounds Made by Insects. — As we descend the scale
of animals, we find in no other a larynx or organ of voice,
and hence all the sounds made by them are not the sounds
of the voice, but simply noises which are for the most part
made by their extremities. The sounds made by insects such
as approach most nearly to those of vertebrate animals, are
produced by vibrations of a membranous plate situated just
over the spiracles. And in general those insects that fly the
most rapidly, and whose wings move the fastest, make the
most noise, while those which move more slowly seem only to
fan the air with their wings. Other sounds are produced by
mastication. Thus, an army of locusts, when eating, makes a
sound which very much resembles the noise of a crackling fire.
A genus of ants make a sound by striking some hard sub-
stance with their mandibles, or arm-like appendages. A
species of beetle that bores in old timber (called the death
watch) makes a sound in a similar way, and if it be answered
by its mate the signal will be repeated : but if no answer be
given, the animal changes its position before it produces its
"tick" again. The shrill sound of the grasshopper and the

What ase is it? What construction increases the intensity of their tones ? 495. What
Is the larynx of reptiles ? What is their voice ? 496. Do insects have a larynx ? In
what different ways are sounds made by insects ?

AND PHYSIOLOGY. 281

so-called locust is made hj rubbing together the anterior pair
of wings, upon the nervures or framework of the wings, on
which are found file-like edges. In a large species of this
kind living in Brazil, which has a drum-like appendage un-
der the wings, the sound can be heard a mile ; and if a man
of ordinary stature possessed a proportionably loud voice, he
could be heard all over the world.

497. Sounds of Mo II use a. — Among the Cephalopods there
are a few individuals which are able to make a clear, bell- like
sound, but the origin of it is unknown.

497. What is said of sounds made by molluscs ?

CHAPTER SIXTH

ICHOROLOGT, OR HISTORY OF THE ORGANS O:^ SECRETION.
THE LYMPHATIC AND SECRETORY SYSTEM.

DEFINITIONS AND DESCRIPTIONS.

Fig. 274.

498. The Body is Constantly Undergoing a Change.—
We have seen that the human body is constantly undergoing

changes in its constituent
parts. The nutrient por-
tion of the food designed
for the support and growth
of the different tissues is
conveyed by the lacteals to
the left sub-clavian vein,
where it enters the general
circulation ; while the par-
ticles which are constantly
set free in all parts of the
body are, by vessels of the
same general character,
called lymphatics, con-
veyed to the blood and
thence to the lungs.

499. The Lacteals a
Variety of the lymphat-
"cs. — A more correct

A, «, Deep-seated Lymphatic Gland, a, 5, Lym- ,

phatics which Supply and Empty the Gland. B arrangement, howcvcr,

a, Superficial Lymphatic, less complex in struc- -^j-ings both SCtS of absOrb-

ture. C, (t, T.vtnnhnfir'. laid finon to show the "^

Valves, c, d,

Lymphatic laid open to show the

ent vessels under the class
of lymphatics, making the lacteals only a variety, since their

49S. How is it that tiie body is constantly undergoing change? 499. What may the*
lacteals be properly called ?

AND PHYSIOLOGY

283

Fig. 275.

Tte Lymphatics of the Body,

284

HITCHCOCK'S AX ATOMY

chief difference consists in the kind of material they convey,
and not in structure or function.

500. The Lymphatics — Their Similarity to Veins and
Arteries — Their Appearance when Injected with Mercury.
— The lymphatics are very delicate, minute and transparent
vessels like the capillaries, remarkable for their uniformity of

Fig. 2t6.

A View of the Vessels and Lvmphatfc Glands of the Axilla. 1, The Axillary Arteiy.
2, Tlie Axillary Vein. 3, The Brachial Artery. 4, The Brachial Vein. 5, The Primi-
tive Carotid Artery. 6, The Internal Jnaiular Vein. 7. The Sub-Cntaneons Lymphat-
ics of the Arm at its Upper Part. 8, Two or three of the most Inferior and Superficial
Glands into which the Superficial Lymphatics empty. 9, Tlie Deep-seated Lymph.atics
which accompany the Brachial Artery. Id, The Lymphatics and Glands which accom-
pany the Infra-Scapular Blood-Vessels. 11, The Glands and Lymphatics accompanyinq:
the Thoracica Lonsa Artery. 1"2, Deeper-seated Lymphatics. 1-3, The Axillary Chain
of Glands. 14. The Acromial Branches of the Lymphatics. 15, The Juprular Lymphatics
and Glands 10. 17. The Lymphatics which empty into tho Sub-Clavian Vein near its
Junction with the Right Internal Jugular Vein.

AND PHYSIOLOGY

235

Fig. 277.

size, of a knotted appearance, and very frequently dividing into
two nearly equal branches. Like veins and arteries, they have
three coats, with folds of the
inner coat for the formation
of valves, giving them a knot-
ted appearance. They com-
mence in a minute net-work
in nearly every organ of the
body, and soon unite into a
few large trunks which take
a direction towards the veins
in the lower part of the neck.
This net-work is so exceed-
ingly delicate, that when filled
with mercury it presents the
appearance of a sheet of silver.
The necessity of such an im-
mense number of these vessels
arises from the constant lib-
eration of the waste particles
of matter w^hich need to be
removed as soon as possible,
that the deposition of new
particles may not be prevented.

501. lymphatic Glands. —
As the minute lymphatics
unite into larger trunks, they ^ view of the Right Lymphatic Tho.

racic Duct. 1, Arch of the Aorta. 2,
Tlioracic Aorta. 3, Abdominal Aorta. 4, Arteria Innominata. 5, Left Carotid. 6,
Left Sub-Clavian. 7, Superior Cava. 8, The two Venje Innoniinatje. 9, The Internal
Jugular and Sub-Clavian Vein at each side. 10, The Vena Azygos. 11, The Termination
of the Vena Ilemi-Azygosin the Vena Azygos. 12, The Keceptaculum Chyli : several
Lymphatic Trunks are seen ojiening into it. 13, The Thoracic Duct dividing, opposite
the Middle Dorsal Vertebra, into two branches, which soon ro-unite ; the course of tho
Duct behind the Arch of the Aorta and Left Sub-Clavian Artery is shown by a dotted
Line. 14, The Dnct making its turn at the Root of the Neck and receiving several Lyin-
• phatic Trunks previous to terminating in the Posterior Angle of the .Tiinction of the In-
ternal Jugular and Sub-Clavian Veins. 15, The Termination of the Trunk of the Lym-
phatics of the Upper Extremity.

500. Describe the lymphatics. ITow many coats have they? What is said of tho net-
work which they make ? Why the necessity of such a multitude ?

286

HITCHCOCK'S A ^^ A T O >.[ Y

pass through small bodies, varying in size from a mustaixl-seccl
to a pea, which are called lymphatic glands, whose design is
not yet clearly understood. They then pass upwards towards
the heart as already mentioned, those of the left side of the body
emptying themselves through the thoracic duct, while those of
the right side enter a tube running parallel to this, called the
Ki^ht Lymphatic Duct. i5, Fig. 2T7.

Fig. 278.

A Front View of the Femoral, Iliac, and Aortic Lymphatic Vessels and Glands. 1, Sa-
phena Magna Vein. 2, External Iliac Artery and Vein. 8, Primitive Iliac Artery and
Vein. 4, The Aorta. 5, Ascending Vena Cava. 6, 7, Lymphatics which are alongside
of the Saphena Vein on the Thigh. 8, Lower Set of Inguinal Lymphatic Glands which
receive these Vessels. 9, Superior Set of Inguinal Lymphatic Glands which receive thes9
Vessels. 10, The Chain of Lymphatics in Front of the External Iliac Vessels. 11, Lym-
phatics which accompany the Circumflex Iliac Vessels. 12, Lumbar and Aortic Lym-
phatics. 13, Afferent Tnmks of the Lumbar Glands, forming the Origin of the Thoracic
Duct. 14, Thoracic Duct at Its commencement.

501. Describe the lymphatic glands. What is the right lymphatic duct?'

AND PHYSIOLOGY.

287

Ly Lymphatics — Effect of

Fig. 279.

502. Material Absorbed
Various Substances Ap-
plied to tlie Slfin— Nutri-
ment Sometimes Intro-
duced through the Sldn —
Thirst Quenched by Wet
Clothes. — These vessels not
only remove useless particles,
but absorb substances applied
to the skin, although some
maintain that this U done by
the veins alone. And this is
sometimes an effective method
of administering medicines
Tvhich it is not expedient to
introduce through the mouth
and nostrils, thus producing
a desired effect upon the cir-
culatory and venous systems
without offending, or in any
manner affecting the senses or
feelings of the person taking
the medicine. For instance,
spirits of turpentine rubbed
upon the hands of many per-
sons, and green leaves of to-
bacco placed upon the ab-
domen, will often produce

A Front View of tlie Deep-seated Lym-
phatics of the Thigh. 1, Lower End of the Aorta. 2, Primitive Iliac Vein. 3, 4, Ex-
ternal Iliac Artery and Vein. 5, Femoral Artery. 6, Section of the Femoral Vein. T.
Vena Saphena on the Leg. 8, Lymphatics near the Knee. 9, Lymphatics accompanj-
ing the Femoral Vessels. 10, Deep Lymphatics going from the inside of the Thigh to
the Glands in the Groin. 11, Lymphatics of the External Circumflex Vessels. 12, Lym-
phatics on the outer side of the Femoral Vessels. 13, A Lymphatic Gland always found
outside of the Vessels. 14, A collection of Vessels and Glands from the Internal Iliac
Vessels. 15, The Lymphatics of the Primitive Iliac Vessels.

502. What do the lymphatics absorb ? What value of this fact at times ? Give a com-
mon effoct of tobacco and turpentine rubbed npon the skin.

13

^88 HITCHCOCK'S ANATOMY

distressing sickness. Mercury, too, rubbed vigorously upon
iilmost any part of the skin, -will in a short time produce sali-
vation, because the minute globules of this metal are forced
through the pores of the skin, and are absorbed by the lym-
phatics. In some cases where disease has so affected the
mouth or passage to the stomach as to prevent the intro-
duction of food, life has been maintained for a considerable
time by nutriment introduced through the skin, by means of
a bath of warm milk. Shipwrecked sailors in an open boat
and deprived of fresh water, can for some time partly assuage
their tliirst by wetting their clothes with salt water, or better
still, by a thorough wetting during a rain storm.

503. Poisons Introduced throi]gli the Skin by llie Lym-
phatics.— The poisoning vrhich frequently occurs from the
contact of the skin with sumach or ivy, is owing to the ab-
sorption of poisonous influence by these vessels. Animal poi-
sons, too, such as the venom of mad dogs, serpents, and in-
sects, are introduced to the general system by the lymphatics.

504. Pi'csrrare Increases their Action.— Pressure greatly
increases the action of the lymphatic vessels. This is seen
in a broken limb which has been tightly bandaged, when the
muscles become very small from the removal of the tissue by
the excessive action of the lymphatics.

505. Venous Absorption — Radicles.— Besides lymphat-
ics, the small veins perform the function of absorption. It is
easily seen that these can perform the same office as the lym-
phatics, since both of them carry their fluids to the heart for
purification, and no other use is made of them on their way
thither. These radicles, or small veins, perform a very im-
portant function in the stomach by the rapid absorption of the
watery portion of all liquids, and its conveyance to the gen-

l3 nntriinont ever convcyerl into tho systom In this vray ? Can thirst bo quenched in
tlli3^vay? 5:3. Do thi; lymphatics ever introduce poison into the system? 504. Ilo^r
docs pressure affect tho action of lymphatics? What example of it? 505. What is said
of absorption bj^ the veins? What important service do the radicles perform in tha
stomach ?

- AND PnYSIOLOGT. 289

eral circulation without passing through the circuitous course
taken bj the food.

50G. Effect of Moisture upon tlie Lymphatics.— Moist-
ure stimulates these absorbent vessels to a morbidly vigorous
action. Hence a person surrounded hy a moist atmosphere
or immersed in water itself, will acquire additional weight.
And as an excessive use of the eliminating organs of the sys-
tem is injurious, locations for houses should be selected as far
as possible on dry places, and not on wet or low land where
heavy fresh water fogs prevail. For the same reason damp
clothing injures the body, because it unduly stimulates the
lymphatics.

507. Amount of Matter taken up by the Absorbents.—
The amount of Chyle and Lymph poured into the blood by
the lymphatics and radicles is about one third of the whole
amount in the body.

ORGANS OF SECEETION.

508. Follicles and Glands.— Character of Secretions.—
Size of Follicles. — The organs which perform the office of
secretion in the body are Follicles and Grlands. The former
of these are small bodies in the form of sacs or tubes, exist-
ing for the most part in the skin and mucous membrane, one
end of which opens upon the surface of the membrane, for the
discharge of its secretion. The secretion poured from these
varies in consistency from the thick wax of the ear, to the
limpid juice of the stomach. The follicles vary also in size
from tubes perceptible to the naked eye down to«those ^Vth of
an inch in diameter.

509. Glands.— The Glands are soft solids of various sizes
(the liver the largest) made up of lobules or small bodies of

606. How does moisture affect the lymphatic action ? How do damp clothes injure tha
■wearer ? 507. What is the amount of matter taken up hy the absorbents ? 508. What
Is the anatomy of the follicles? Of what character U their secretion? What la their
size ? 509. What ia a gland ?

290

HITCHCOCK'S ANATOMY

Fig. 280.

Iiilunuc btiucLiitc of -x Giind (the Parotid).

minute proportions, each of which has an artery, a vein, and
a duct to carry away the secretion. These ducts unite with
one another, until they form one tube called the principal
outlet of the organ. In some glands these lobules are quite

Fig. 281.

Aorta. Thoracic Canal. Lymphatic Ganglions.

( Eadicles of the Chyliferous
••■'' I Vessels.
— Intestine.

Lymphatic Vtssels. Mesentery.

Chyliferous Vessels.

ANATOMY AND PHYSIOLOGY. 291

large — one fourth of an inch in diameter — while frequently
they are nearly the size of a niustaid seed. The color is also
various. That of the liver is a dark red, the pancreas of a
pale white or gray, the little gland in the inner angle of the
eye pink, and the kidneys a reddish yellow.

510. F u 11 c t i 0 n 0 f S e c r e 1 1 0 n . —The function performed by
these vessels is an exceedingly curious, and not easily ex-
plained phenomenon. For from the blood are eliminated by
the various secretory organs, bile, saliva, perspiration, tears,
etc., none of which exist there as such^ but they seem to be
formed from the chemical elements in the blood by the glands
themselves.

511. Effect of the Emotions upon the Secretions.—
The mental emotions greatly affect the secretions. A -person
in fear is often covered with a cold perspiration, and in some
persons in the same situation the salivary glands cease to act.
On the other hand the thought of savory food has been known
to cause the saliva to issue in a jet from the sides of the
mouth.

512. Reserve Glands. — Some glands also act only on parti-
cular occasions, as in the case of a broken bone, or cut in the
flesh, when the appropriate vessels set themselves at work to
repair the injury.

513. Secretion after Death. — Certain secretions are con-
tinued for a time after the death of the individual. Thus it
has been observed that the hair and nails grow considerably
after death, provided the disease was a rapid one, so that the
system was not reduced by loss or degeneracy of the blood
and nervous system. It is also related that in dissecting the
poison apparatus of a rattle-snake, the poison was secreted so

Give the minute anatomy of the glands. Describe their ducts. Mention their various
colors. 510. What is the use of the glands ? Do the secretions exist ready formed in the
blood? 511. What is the effect of the feelings upon secretion ? Give an example. 512,
What is said of reserve glands? 513. What is said of secretions continuing some time
after death ? Give an esamijle.

292 HITCHCOCK'S ANATOMY

fast that it was necessary to dry it off occasionally during the
dissection.

514. Yi carious Secretion. — ^Another curious phenomenon
connected with this subject is vicarious secretion, where one
organ performs the whole or part of the office of another.
This is often seen in the function of the lungs and liver, where
one imperfectly performing its office, is aided by the other.
This vicarious secretion is still more apparent between the
liver and skin. For in the disease known as Jaundice, where
some obstruction is offered to the passage or secretion of the
bile, it is poured out by the skin, coloring it deeply yellow,
and in some instances it has been known to stain the linen,
which is worn next the skin, perceptibly yellow.

515. Ductless Glands. — In connection with this subject
it is proper to mention a class of organs known as Ductless
Glands, or bodies which have the form and general structure
of glands, but no duct or outlet, and form no secretion, as do
the true glands. These are the Spleen, the Tliymus and
Thyroid Glands, and the Supra Renal Bodies. Of these only
the former will be described here, since the latter are most
perfectly developed during the earliest, or fetal stage of exist-
ence.

516. The Spleen. — The Spleen measures in different indi-
viduals from four to six inches in its longest diameter, and is
situated under the left extremity of the stomach. (Fig. 282,
p. 293.) It is of a reddish blue color, convex on its external,
and concave on its internal surface. It is very abundantly
supplied with blood-vessels, and consequently vascular or
spongy in its structure. (Fig. 283, p. 293.) Upon a close
inspection it is found to be made up of corpuscles from one
third to one sixth of a line in diameter, each of which is com-
posed of nucleated cells about 5 aVoth of an inch in diam-
eter. (Fig. 284, p. 293.)

514. State the principle of vicarious secretion. What remarlcablc facts in this connec-
tion about j.annclicc? 515. Describe the ductless glands. What are their names? At
what period of life arc they the most fully developed ? 516. Describe the spleen.

AND PHYSIOLOGY.

293

Fig. 282.

Fio;. 283.

Sliows tho Internal Face of tlic tiplcen Section of tLe Spleen.

whero it touches the Stomach. 1, Supe-
rior Extremity. 2, Inferior Extremitj^ 3, Posterior Part of the Concave Fr.ce. 4, An-
terior Part of the same. 5, Fissure of the Spleen. G, Splonic ArtorJ^ 7, Splenic A'ein.
8, 8, Anterior Edge of the Spleen. 9, 9, Its Posterior Edge.

Fig. 284.

Section of the Spleen magnified.

294 HITCHCOCK'S AXATOMY

517. Function of this Organ.— Produces and Destroys
the Red Blood Corpuscles.— As already stated there is no
duct or outlet to this organ, or evidence of any secretion out-

FiG. 285.

Small Portion of the Spleen very highly magnified, showing two corpuscles and the
minute Blood- Vessels.

ward. But the idea has occurred to physiologists, though
with no positive proof as yet, that a kind of secretion is pro-
duced by the spleen which is poured directly into the blood,
and consequently there is no necessity for any outlet. And
again experiments have been carried so far as to give plausi-
bility to the idea, that this organ is designed to 'produce
hlood cojyicsc^es, and at the same time use up those that are

517. Of -what use is the spleen? What is said of it as an organ for producing blood
corpuscles ?

AND PHYSIOLOGY, 295

no longer of service to the body. Certain it is that no other
organ in the body has as yet been discovered which subserves
this purpose, and equally certain that in cases, where large
wounds are to be healed, and in certain other conditions of
the body, the white corpuscles are greatly increased in num-
ber.

518. The Skin. — Among those organs whose offices are
those of absorption and secretion, the Skin finds a prominent
place.

519. Made up of Three Membranes. — This is a membrane
simple in its general aspect, but under the microscope it is
found to be composed of no less than three distinct layers :
the Epidermis, Basement Membrane, and Corium. It covers
every part of the body, except the portion immediately sur-
rounding the various orifices, and those portions of the ex-
tremities covered by the nails. It is highly elastic, as may
be seen by the gaping of a long gash, and possesses a certain
amount of contractility, owing to some muscular fibers con-
tained in it.

520. Papilla;; their Size. — Upon several portions of the
body the skin is roughened by small protuberances, either
arranged in a circular form, or in rows, which are supplied
w^ith one or more loops of

nerves. These are termed Fig. 286.

Papillaj, and are found most
abundantly in the extremi-
ties, and especially upon the

palms of the hand and soles '^^^MIHW^mM^B

of the foot. They vary in ^M^^S^^m^.

height from s^rd to ^Vd of a

fdi
in difierent parts of the body.

^^.^ PapillEB from Palm of the Hand, magni-

Ime, bemg of different lengths fied tinrty-fivo times.

519. Of what three membranes is the skin made up? State their general proper-
tics. 520. What are the papillse ? Where are they found in the greatest numbers?
Stat© their siza

18*

296

HITCHCOCK'S ANATOMY

521. Epidermis or Cuticle; Has no Vitality.— Pigment
Cells. — Composition of Pigmcnt-Celh. — The outer layer of
the skin is called the Cuticle or Epidermis, and bears the
same relation to the true skin, that the outer bark of the tree
does to the inner. In thickness it varies considerably in the
different parts of the body. It is tt J o-th of an inch thick on
the chin, cheeks and brows, and y^ th to ^th of an inch thick
on the soles of the foot. It is merely a layer of albumen —

FiG. 287.

Frj. 288.

Vertical Section of Epidermis from a
Negro, o, Deep Cells loaded ^vith Pig-
ment. &, Cells more clev.ated and some-
■n-hat flattened, c, Scaly Cells at the Sur-
face.

Highly magnified Pigment-Cells. A.
Scales of the Epidermis filled with Pig-
ment Cells which are seen separate at &.
B. Pigment Cells from the Choroid Coat
of the Eye.

the same substance as the white of an egg — and is secreted
by the true skin, in the form of scales, which are closely
compacted together, and it is in this form that they are de-
tached from the body by washing and friction. In some
cases, however, it is detached in large patches, so that after
certain skin diseases have run their career, the whole epider-
mis of the hand with the nails adherent may be removed in
the manner of a glove. The epidermis contains no blood-
vessels or nerves, and consequently no vitality, it being merely
a secretion which hardens into a semi-transparent membrane.
A part of the cells of the true skin, however, instead of se-
creting the epidermis, produce what are termed the Pigment

521. Describe the epidermis. To what does it correspond in the tree? State its thick-
ness and chemical composition. What vessels and what cells docs it contain? ,Wher«
are tho pigment cells shown ?

AND PHYSIOLOGY.

297

Cells, Tvhich give color to the skin. These cells are best ex--
hibited in the eje where the pigmentum nigrum (black paint)
is secreted, and are of the same kind with those in the epi-
dermis. The J r.ro oval or rounded granules, measuring
•Tou- TTuth of an inch in diameter, and one quarter of this in
thickness, sometimes presenting a polygonal or stellate form.
They have nearly the same composition as the coloring matter
of the cuttle-fish, which contains a much larger proportion of
carbon than is contained in most organic substances, namely
58} parts in bundred. The development of tbese cells de-
pends mainly upon exposure to the sun's light. Hence v>-3
see that persons with a fair skin become of a darker hue, iF
exposed to the strong and direct light of the sun.

522. Tlic Nails; Mode of Growth; Rdto of Growtli.—
The Nails are composed of the same material as the epidermis,
being merely an altered form of it. When their newest por-
tions are examined with the microscope, they are found to bo
nucleated cells closely resembling those of the epidermis,
Epithelium cells. The
nail increases in length
by successive additions
to its root, which push
it forward over the end
of the finger, while at
same time it receives
additional layers from
the skin beneath. The
nails of the hands grow
about two fifths of a
line per week, while
those of the foot re-
quire four times that period for the same amount of growth.
The blood-vessels of the nails are very abundant, and arc

Fig. 2 so.

Section of the Thumb, r. La?t Tone of tl
Thumb, h. Epidermis reflectcil on the Nail.
Nail. d. Epidermis aL the Point of tho Tiinib.

What is very remarkable about tho chemical composition of this pipnont? What
does tho development of these cells depend on? o22. Of what composition arc tho nails?
Of what kind of cells are they ? IIow fast do tho nails of the hand grow ?

29S . HITCHCOCK'S ANATOMY

situated just within the corium, into which the nail barely
dips. And so numerous are these, and of so low a degree of
vitality, that frequently the nails grow for a short distance
after death. When the nails are badly injured, they are sel-
dom perfectly regenerated, because of the injury done to the
vessels and laminae. A rudimentary nail sometimes is found
on the second joint, when the first is destroyed. Cases are
also on record, where the nails have been shed and renewed
periodically. The nails are thickest at their most convex
portion, instead of their edges, and increase in thickness from
the base to their free edge. They grow only so long as they
are cut, and among the literary class of the Chinese, who
never cut their nails, they are said to attain only a length of
two inches. The time necessary for a nail to grow its whole
length, varies from twelve to twenty weeks.

522 a. Basement Membrane of the Skin. — The middle
layer of the skin is simply a basement membrane, and is in
fact the mucous layer of the epidermis. It is, however, of
little importance in the functions of the skin, and is believed
to be a separate layer merely because, when it is immersed in
a solution of potash in connection with the epidermis, the
latter is dissolved, while the former is unchanged.

523. The Corium; its Composition,* Nerves of the
Corium. — The Corium or internal layer is the true skin,
since it possesses the vitality and sensibility of this membrane,
and contains all its vessels. It is made up of white and yel-
low fibrous tissue, the white predominating, except in those
parts w^here occasional extension is required, where the yellow
exists in larger proportion. The blood-vessels of the corium
are very abundant, terminating in the minute tubes which
supply the sudoriparous and sebaceous glands : the proof of
the abundance of which we have in puncturing any part of

Why do the nails sometimes grow after death? Why do the nails seldom grow nat-
urally after an injury? At what portion arc the nails the thickest ? 522 a. What is tho
middle layer of the skin ? 523. Of wliat is the corium composed? What is said of tha
abundance of blood-vessels in the corium ?

AND PHYSIOLOGY

299

the skin \\ith the finest needle, when a drop of blood is sure
to follow. The nerves of sensation too are very abundant, as
we know by the insertion of a pin into any part of the body,
which invariably pains us, because we have wounded a nerve,
and not an expanded surface, like a membrane.

524. Sebaceous or Oil Glands. — The Sebaceous Glands
are small elongated sacs which are generally gathered in
clusters about each, of the

hairs of the body, varying Fig. 290.

in number from four to twen-
ty. They pour their secre-
tion into the hair-canals near
their orifices, and are most
abundant in the parts of the
body most exposed, as in the
skin of the nose. Their se-
cretion in most places resem-
bles fat, although in the pas-
sage of the external ear a
substance resembling wax
(cerumen) is poured out.

524ti5. Parasite in the
Sebaceous Glands. — It is a
fact curious, if not at first
sight revolting, that there is
very constantly found in the

outlets to many of the sebaceous glands a parasitic animal, as
represented by the cut. (Fig. 291, p. 300.) The occurrence
of this animal in almost every individual has led one anat-
omist to call it a '' denizen" of the human body.

525. Sweat Glands. — Length of Sweat Tube in the
Human Body. — The Sudoriparous or Sweat Glands essen-

What of tlie nerves in the corium ? 524. What are the sebaceous glands ? Where are
they the most abundant ? What is their secretion ? 524 a. What Is said of the parasite
in the skin ?

A View of the Cerumen Gland
formed by the Contorted Tubes. 1, 1;
The Tubes. 2, The Excretory Duct.
3, The Vessels supplying it.

300

HITCHCOCK'S ANATOMY

Fig. 291.

Parasites of the Sebaceous Glands.
Orifice of the Gland, b. Short Variety.

Two seen in their ordinary position at the
LoniT Varietv.

tially consist of long tubes convoluted and twisted upon them-
selves, (Fig. 293, p. 301), located just beneath the corium,
several of which join to form an outlet, which passes through
the epidermis in a spiral manner, so that as it opens exter-
nally, a valve is made preventing the entrance of substances
from without, but allowing a ready exit to all substances to be
discharged externally. The size of the gland proper is about
■y^th of an inch in diameter, and that of the tube is about 4 |-oth
inch. The outlets of these tubes (Fig. 292, p. 301,) are called
the pores of the skin, and are somewhat larger than the diam-
eter of the tubes. The most remarkable fact, however, con-
nected with these glands, is their immense number in the sys-
tem. Each tube when straightened measures on an average one
fourth of an inch in length, and by actual count there are at
least 2,800 in every square inch of the body. (Fig. 293,
p. 301.) Now the number of square inches in a man of or-
dinary height is 2,500, which would make the number of
pores or op3ning3 about -7,000,000, or the whole length of

625. Wliat is tho frenoral outline of the sweat plands ? What is their size !
on every square iach of the body ? What is their as^Tcgato length ?

How many

AND PHYSIOLOGY, 301

Fig. 292. Fig. 293.

Skin of the Palm showing Kidges, Fur-
rows, Cross Groves, and Pores, or Orifices
of Sweat Ducts.

tub,e 145,853 feet, or 48,611
yards, or nearly 28 miles.
Dalton says, 153,000 inches
or two and a half miles.

526. The Perspiration.
— Sensible and Insensible
Perspiration. — The secre-
tion poured out by these
glands, is a transparent liquid
of an acid reaction, and of a
saltish taste, commonly known
as sweat or perspiration. This
is produced in two forms,
known as sensible and insen-
sible perspiration, which is
escaping from the body in

one of these forms constantly during health-j the sensible being
given off whenever excretion i3 so great as to leave moisture
upon the skin.

520. Deecribe tlio pei-siiiratioo. W'liattwolormsof it? •

Vertical Section of the Sole of the Foot.
a. Epidermis. &. Papillary Structure.
c. Cutis, d. Sweat Gland magnified forty-
diameters.

;c2

HITCHCOCK'S ANATOMY

527. Amount of Walery Yapor Discharged from the
Cody. — The amount of fluid which is lost from the body both
bj the skin and lungs, is about eighteen grains per minute,
eleven bj the skin and seven by the lungs. This amount,
however, varies exceedingly with the state of the health and
the dryness or moisture of the air, which, as already men-
tioned, regulates the temperature of the system.

528. The flair. — The hair is distributed over nearly every
portion of the human frame, and presents differences according

-pj^ 294 t^ ^o^j s^^j ^^^^5 <^^ individ-

ual peculiarities. In length,
the hair is most fully devel-
oped on the heads of females,
sometimes equaling the length
of the body, while in male
beards it seldom reaches to
the waist. The coarsest hair
is also found on women.

529. Size of the Hair-
Oil Glands . — In diameter the
hair varies from yjo-th to
ooVotti of an inch, and its
section is always of an oval
outline, but never circular.
'Nor is the hair of a uniform
diameter, but it is spindle-
shaped almost always, and
terminates m a point. At its
base it expands into a bulb
which is lodged in a sac in
the true skin, as is seen in Fig. 295, p. 303. Just beneath the
epidermis one or more glands are situated which empty their

^

Sections of Human Hair, a, &, Trans-
verse Sections showing the Cortical (or
external) and Medullary (or internal) Sur-
face, c, d, Longitudinal Sections of Hair.
c7, Shows the overlapiilngof the Epidermic
Scales of which hair is composed.

• 527. What is the amount of watery.fluid discharged from the body ? 528. What is said
of the distribution of tho hair? How long has the hair been known to grow? 529.
What is the diameter of the hair ? What is the shape of it? What glands empty their
content* upon the base of each hair ? ... .

A-^B PHYSIOLOGY,

303

contents into tlie same pore in
which the hair itself is lo-
cated. This secretion is an oil
which keeps the hair in a
smooth and moist state.

530. Tiieir Number.— The
number of the hairs varies
with the color and portion of
the bodj. In one case there
were found on the same sur-
face 147 black hairs, 162
brown, and 182 blonde. On
a surface one fourth of an
inch square the same author
found on the scalp 293 hairs
and on the chin 39.

Fig. 295.

Layer from Scalp.
Hair c, Follicle.

a, Oil Glands. &.

531. Their Distribution
and Direction— They are

implanted either singly or in twos or threes, or even four
or five together, and their direction is rarely perpendicular
to the skin, being, in a natural state, downwards. They may,
however, be changed in their direction by persevering efforts,
as is sometimes seen by the brushing of the hair away from
the forehead. ^

532. Chemical Composition— Durability.— They differ
from most tissues of the body by containing ten per cent, of
sulphur. This, together with the fact that they contain a
large per cent, of nitrogen, accounts for the unpleasant odor
given off while burning. They resist decomposition better
than most of the tissues. Those of Egyptian mummies re-
main quite unchanged. And it is owing to their durability
that they are used as. relics of departed friends.

530. What is said of the number of hairs on the body ? 531. How are they distributed,
ond what direction do they take? 532. How do they differ from most other tissues ia
chemical composition ? How durable is hair?

304

HITCHCOCK'S A K" A T O M Y

Fig. 296. 533. Constitution. — In

constitution the hair con-
sists of three distinct por-
tions, an epidermis or outer
portion, a fibrous, and a med-
ullary portion. The epider-
mis is arranged in the form
of ring-like scales, whici
overlap each other like tlic
shingles of a house, and is
about ioVoth of an inch
thick (Fig. 294, d). Hence
we see the reason why we
can brush the hair in only
one direction. The fibrous
portion makes up the prin-
cipal bulk of the hair, and
is composed of longitudinal
cells, which contain paint
granules and air cavities which give the color to the hair.
The medullary portion constitutes the central part of the hair
(usually from one third to one fifth its diameter), and is made
up of cells varying in diameter from e oVo'^^ ^^ o o io otti of an
inch in diameter.

533 a. Color. — The color of the hair is thought by some
to be owing to the iron contained in it, since it is said that
there is the most of this metal in the darkest hair.

533 h. Pliysical Properties. — Hair is so elastic that it
will stretch without breaking to nearly one third more than
its original length. A single hair of the head will support
six ounces without breaking. It readily absorbs moisture,
and is dry and brittle or moist and soft, according as the skin
or atmosphere is dry or moist. The beard is abundantly

Highly Magnified Eoot of Ilnir. «, Shaft
of Hair. 6, c, Epidermic Sheath of Hair, d.
Dermic, or External Sheath of Hair, e, Epi-
dermic Scales.

533. What three portions is each hair constituted of? What makes the principal part
of each hair? 533 o. What is it possible that the color of the hair is owing to? 5S3 J
What is the strength of the hair ?

AND PHYSIOLOGY,

305

Fig. 297.

-supplied Tfith blood-vessels, as
is seen bj the cut.

533 c. Rale of Growtli.—
In one set of experiments
the hair has been found to
grow seven lines per month.
Frequent shaving greatly
increases its growth. It also
grows faster by day than
by night, and in summer
than in winter.

A small portion of the Follicle of a Hair
of the Beard, with the Arteries supplying it— very highly Magnified. 1, Its Follicle. 2,
Its Pulp. 3, The Trunk of the Hair without the Follicle. 4, 4, Two Arteries going
to the Base of the Follicle. 5, 5, Their Distribution. 6, 6, The Eeticulatcd Tissue of
the Follicle.

FUNCTIONS OF THE SKIN.

534. The Skin a Covering.— The skin is the natural cov-
ering of the body of man, and he is not furnished with any
further and more complete covering, as is the case with many
of the lower animals, since he is endowed with an ability to
devise means of covering better suited to his condition than
one of hair, wool, or feathers.

535. Use of the Epidermis — To Protect the Nerves. —
The epidermis is of use to protect the corium and its vessels.
Without this covering many of our sensations acquired through
the skin would be very painful. The contact of the softest
Eider down with the exposed nervous filaments would impart
tlie acutest pain, and the rays of the noonday sun would in-
flict the keenest torture. The body could not endure the
lightest clothing, and even our motion through the air would

533 c. What is said of the rate of growth of the hair ? 534. What is said of the sldn as
a covering ? 535. What is said of the epidermis as a source of protectioa to the delicate
nerves of touch ?

306 HITCHCOCK'S ANATOMY

be a source of misery. But these delicate nerves are pro-
tected by an insensible membrane, which, though hard, elas-
tic, and a very perfect guard of these faithful sentinels, per-
mits all the necessary impressions to pass through them. The
epidermis also guards the most delicate parts in a careful man-
ner, by thickening its substance over the ends of the fingers,
and in all places where sensation is most acute. It is also
speedily renewed where friction or accident removes it, as on
the palms of the hands and soles of the feet.

536. To prevent Absorption. — Another important use of
the epidermis is to prevent undue absorption. For the lym-
phatics only penetrate the corium, and cease at the under sur-
face of the epidermis. Consequently but very little fluid can
enter these vessels unless the epidermis is removed or satu-
rated with fluid Were it not for this protection, almost every
liquid substance brought in contact with the surface of the
body would at once be introduced into the general circulation,
thus exposing the system to serious danger by absorbing poi-
sonous matter.

537. To Preienl Excessive Perspiration.— Danger from
an opposite direction is also warded off by the impenetrability
of the epidermis. Were it not for the tortuous direction which
the outlets of the sweat glands take as they empty themselves
upon the surface of the body, an excessive amount of water
would be set free, and thus greatly reduce the system. But
owing to this arrangement of sweat ducts, it is only when the
system is very much stimulated that any considerable amount
of water can be discharged by sweating. Were not this the
case, the body would often be reduced to a low state from the
loss of the watery portion of the blood, as is sometimes seen
in excessive sweating.

538. Use of the Corium — Contains the Blood-Vessels

53G. What is tlio use of the cpiderinis to prevent undue absorption ? 537. How docs
the epidermis prevent undue perspiration?. What harm would result from excessive
sweating?

AND PHYSIOLOGY. 307

and Nerves— AmoiHit of Waste Escaping from the Skin.
— In the cerium, or internal layer of the sliin, resides the vi-
tality. Here the arteries terminate in the capillaries and the
nerves double upon themselves^ producing the highest sensi-
bility to external impressions. So that when any function of
the skin is spoken of, reference is usually made to this inner
layer. And we see that the skin is not only useful as a pro-
tection and covering to the body, but is of great value as an
excretory apparatus. And in this office the skin is pecu-
liarly valuable, since it removes a great amount of matter
from the system that the lungs cannot remove. The actual
amount of waste matter escaping daily from the skin is given
variously by dilFerent writers. All, however, make out an
average of from thirty to forty ounces, or if condensed to
water, about two pints. A proof that the vapor of water es-
capes in the form of insensible perspiration is had by placing
the dry hand upon a cold glass or polished metallic substance,
when moisture in a few seconds condenses on the surface.

539. Uses of the Oil Glands— Renders tlic Hair Soft
— Softens tlie Skin — Protects the Eye — Guards the
Mem bran a Tympani.— The function of the sebaceous, or oil
glands of the skin seems to be the secretion of substances pro-
tective to the skin. These are mainly oily products, and are
given off at the roots of the hair, so as to give it flexibility,
that by its stiffness it may not irritate the skin. The oil tubes
are most abundant on those parts of the body which are most
exposed, and especially the face and neck. The design of the
secretion seems to be to give flexibility to the skin, to prevent
the heat and air from drying it so that it would crack in many
places, and also to lubricate it when brought into contact with
foreign substances, as is the case so frequently with the hands.
The oil of the skin also prevents moisture from adhering to it,
and thus its functions can be more perfectly carried on, and

53S. Whore lies the vitality of the skin ? What otlier use than a protection is the
skin ? How much waste matter escapes daily from- the skin ? How many pints ? 539.
What is the use of the oil glands? How does it aSfuct tho hair? What value does it
Impart to the skin ? • •

308 HITCHCOCK'S ANATOMY

it will not retain all dust -which chances to fall upon it. At
the flexions of the joints, and all those places where two sur-
faces of the skin are frequently brought in contact, this oily
secretion is abundantly poured out, in order that there may
be as little friction as possible between the opposing surfaces.
Upon the edges of the eyelids is situated a row of glands which
pour out their secretion in such a manner as to retain the tears
— the lubricating fluid of the eye — when produced in their
ordinary quantity ; but when in excess, as in weeping, they
run over their boundaries, and flow down the cheek. The us3
of these glands may be well appreciated in some diseases of
the eye, where the tears constantly run down upon the cheek,
producing irritating sores.

In the passages of the ears we find the same glands, al-
though their secretion is of a somewhat difierent character.
Here it is a clammy, viscid substance, of a yellowish color,
and from its appearance it is called the wax of the ear. Its
service is to prevent dust and fo eign substances generally
from gaining access to the internal ear, where they would
injure the sense of hearing.

HYGIENIC INFERENCES.

540. — 1. Great Value of this Membrane in the Ani-
mal Economy . — From the complicated structure of the skin,
we see that this membrane is of great service in the animal
economy. It stands next in importance to the lungs as an
excretory organ, and if its functions are interrupted the whole
system very soon feels the disturbance.

541.— 2. Its Health Requires Cleanliness. — The skin
must be kept clean to secure the proper functions of the per-
-spiratory glands. This not only implies the necessity of fre-

llow (l(jos it nfft'ct the skin nt the joints? Of what service is it totheej'e? Of what
to the ear? 540. State the relative value of the skin in the animaJ economy. 641. Why
U cleanli.ness essentia! for the health of the skin ?

AND PHYSIOLOGY. 309

quently washing the whole surface of the skin, but also the
frequent change of the bed-clothes, under-clothes, etc. And
it should be a fixed rule with every one to change the linen
and under-garments both night and morning ; that is, the
under-garment worn during the day should not be worn at
night, and the reverse.

542. — 3. Must be Kept at a Uniform Temperature.-—
We also learn that the skin should be kept at a uniform tem-
perature, and up to its normal standard. It therefore needs
proper clothing, not so much in the coldest weather — for then
our feelings will impel us to do it — but at the changes of tem-
perature so common and so great in our climate in spring and
autumn, for then we are too apt to neglect it because we feel
no especial inconvenienc3, and yet at these times there is
more danger of disease from a want of proper clothing than
at any other season of the year. We seldom injure ourselves
by too much clothing, because we can easily throw of superflu-
ous garments, but often do it by too small an amount of pro-
tection. An important rule for every one is, when going
abroad even a short distance from home, to carry with him
an over garment when exposed to evening air.

543.-4. Must Come in Contact with the Air.— The
skin imbibes oxygen from the air, and hence it is important
that air be brought in contact with this membrane. The
clothing should be worn so loosely that a thin layer of air Avill
be in contact with nearly every part of the skin.

544. — 5. Needs Friction. — Frequent and thorough dry
friction applied to every part of the skin greatly promotes the
health, not only of this membrane, but of the whole body. So
smooth arc the clothes we generally wear next the skin, that
but little stimulus is received by them, and hence a thorough

542. What is necessary for the temperature of the skin, especiallj for chan-res in
■weather? What is said of an over-coat as a constant traveling companion ? 54-3. Why
.fihonkl the skin have air in contact with it ? 644 What is the use of friction to tho
skin?

310 HITCHCOCK'S ANATOMY

rubbing of the whole body every night and morning -vvill aid
greatly in this matter.

545. — 6. Injurious Effects of Moisture upon the Skin.
— Moisture if applied to the skin for a considerable length of
time interrupts its functions, and accordingly we infer that
wet or damp clothing should not be allowed to remain on the
body any longer than is absolutely necessary. If, however,
dry clothing cannot be procured immediately, the body should
be kept in vigorous action of some kind until the clothes can
be changed. This inference is of equal application, whether
the whole of the body be wet, or only a portion of it, as the
feet.

546.-7. Service of a Daily Cold Water Bath.— We in-
fer again that a daily cold water bath is of great service for
all students and sedentary persons who are in health. Not
only is it desirable on account of cleanliness, but a serviceable
shock is thus imparted to the nervous system. It, however,
should be taken as speedily as possible, the essential thing
desired being, that pure water should be spread over the
whole surface of the body, and after it that the skin should
be speedily and vigorously wiped dry. The secondary effect,
however, the stimulus imparted to the nervous system by the
shock, is by no means an unimportant issue to bo gained.

COMPARATIVE DERMATOLOGY.

547. Covering of Mammals. — The skin of mammals very
closely resembles that of man, with the exception of the epi-
dermis and its horny appendages, which are usually covered by
hair. The fat tissue, too, just beneath the skin, is often develop-
ed in a surprising degree, and the corium in many instances is
very thick. Some have horny scales, and others long plates.

545. What arc tho injurious effects of too much moisture applied to the skin? 546.
What is said of a daily bath, and what regulations concerning it? 547, What is^said o|
the covf rinij of mammals ?

AND PHYSIOLOGY

311

548. Callosities. — In many of the rodent or gnawing ani-
mals, the carnivora and camels, the epidermis about the joints
becomes very thick, making callosities or pads for the sup-
port and protection of the parts exposed.

549. E p [ d e nil i c Scales . — True Epidermic Scales are found
on the tails of many animals, such as the Beaver.

550. Horn of Rhinoceros. — The so-called horn of the
Rhinoceros is nothing but a thickening of the epidermis until
is assumes the form of a hollow cone.

551. Varieties of Hair.- The hairs upon the external
surface of mammals either present no greater irregularities

Fig. 298.

Fig. 299,

Hair of Sable.

Hair of Musk Deer.

than do those of man, or they are slightly rough, like those
of the Squirrel, or knotty, as in the Bear, or furnished with
pointed processes, like the teeth of a saw, in other animals.
Some of these peculiarities are exhibited in the adjoining
cuts. The spines of the Porcupine and Hedgehog differ from
hairs only that they contain the same materials in a more con-
densed form.

552. Glands of the Skin. — Cutaneous and sebaceous
glands are present in most mammals very abundantly. The

5^. To whicli membrane of the skin do the callosities of camels, etc., belong? 5i9,
Where are epidermic scales found ? 550. What is the horn of the rhinoceros ? 551. What
are the varieties of hair In different animals ? 552. What is said of glands of the skin

312

HITCHCOCK'S ANATOMT

Fig. 300. Fig. 301.

B c

Transverse Section of Hair of Pecart

A. B. Hairs vf Squirrel. C. Hair of Indian Bat.

latter secrete an unctions fluid, which is usually of a strong

smell.

553. Skin of Birds. — The Skin of Birds is thin and desti-
tute of cutaneous glands, except one at the tail, which is gen-
erally present. The whole body is covered by feathers, except
certain parts of the head, legs, and feet. There it becomes very
much thickened, forming callosities, wattles and combs, in
which, beside the cellular tissue, are found the elastic and erec-
tile tissues, as well as red and blue cells of coloring matter.
Upon the toes and feet are found plates and scales of horny tissue.

554. Feathers of Birds. — The Feathers of Birds are
made up of the Quill and Vane: the former giving it attach-
ment to the body, and the latter forming its expanded surface.
The Vane is made up of a small number of laminae or plates,
which both form a light and firmly resisting medium to the
air, and serve to retain the heat within the body. When per-
fectly formed the laminae are furnished with a booklet at their
free extremities, by which they are attached to each other,

553. Wliat is the thickness of the skin of birds compared with that of mammals?
What are the wattles and combs? 554. What two parts are feathers made np of? Why
oje the laminai furnished with a barb at each extremity? What is the design of their
overlapping each other ? ^

AND PHYSIOLOGY. 313

thus making each feather an impenetrable plans, surface.
The feathers also overlap one another to a considerable de-
gree, and as they thus contain air, and are themselves non-
conductors, they afford the most perfect protection to the body
against the cold.

555. Skin of Ampliibia. — The naked Amphibia, such as
the Frogs, have a smooth slippery skin, which is continually
being cast off in patches or shreds. This skin surrounds the
solid parts of the body very loosely, and spaces for lymphatic
vessels are found beneath. It is always composed of several
layers of fibres which lie at right angles with each other.

556. Scales of Serpents. — Upon some serpents, scales are
found which overlap one another, like the shingles of a house,
as is also the case with fishes. Scales with tubercular spines
are met with on some reptiles, and in some instances, as those
of Crocodiles and Tortoises, they contain bony matter, and
coalesce with the bones of the skeleton.

557. Exuviation of Serpents. — Many Serpents cast their
skin several times during the year, either by piecemeal, or by
drawing off the whole at once. One species of Tortoise does
the same thing, as well as several Lizards. This is an anal-
ogous function to the moulting of birds, and shedding of the
coat in mammals. This generally takes place in Spring,
but frequently upon a change of weather several times in the
year. At each period, when this is effected by the Rattle-
Snake, a new segment is said to be added to the tail, which
seems quite probable, since the rattle is merely a condensed
portion of the epidermis.

558. Scales of Fishes. — Classification of Fishes by
their Scales. — Fishes have an Epidermis which is sometimes
covered with scales, and sometimes not, though always lubri-
cated most thoroughly by a copious mucous secretion. The

555. What Is said of the skin of frogs ? 556. Do serpents ever have scales ? 557. What
Is the exuviation of serpents? When does this take place? What peculiarity in the
rattld-snalte 7 55S. How are the scales of fi&hes arracged?

314 HITCHCOCK'S ANATOMY

scales are sometimes disposed in an imbricated manner upon
the body, and are not situated in the epidermis, ''but really
in the skin, and included by it." The scales contain both
phosphate and carbonate of lime as a rule. Their shapes are
various, though Professor Agassiz, the best living authority
on fishes, has grouped all bony fishes under four orders, de-
pendent mainly upon the form of the scale. First, the Pla-
coidians, including such fishes as the Sharks and Rays, where
the scales are either large and covered with bony tubercles,
or simply with small enameled scales. Second, the Ganoi-
dians, including the Sturgeon and bony Pike, which have
angular bony plates coated with a thick layer of enamel.
Third, the Otenoidians, such as the Perch, which have hard
scales jagged on the outer edges, like the teeth of a comb.
Fourth, Cycloidians. These have soft and circular scales with
simple margins. In this order are found the Herring and Sal-
mon. Sometimes the scales are provided with a hook-like
process, which overlaps and fastens itself into a depression in
the scale beneath.

559. Tegument of Articulata.— Horny Case of In-
sects.— The Tegumentary envelop of the sub-kingdom Arti-
culata has already been described under Comparative Oste-
ology, since the skin of many of this sub-kingdom, especially
the Crustacea and insects, is in reality the only skeleton these
animals have. Insects have a covering sometimes leathery
and soft, and sometimes horny and solid, which contains a
peculiar proximate (chemical) principle known as Chitine.

560. Mantle of Molluscs, — In Molluscous animals, a
dermis, which is a muscular skin, envelops all the viscera,
and hence is called the cloak or mantle, w^hich secretes the
hard calcareous covering known as the shell. Generally the
shell is external to the mantle, as in the Clam and Oyster,

What are the four orders dependent upon the form of the scale? Who is the author
of this arrangennent ? Give examples of each. 559. What is the covering of the articu-
lata? What is peculiar about its chemical composition ? 660. Describe tlii) outside cov-
ering of molluscs.

AND PHYSIOLOGY. 315

but often, as in the Cjprgea or Cowry, the mantle extends
over the shell.

561. Radiates. — With the exception of the hard external
skeleton of these animals already described, their proper skin
is mostly thin and soft, allowing of great flexibility and some-
times of great expansion and contraction.

The Protozoa have a very delicate, cutaneous envelope,
sometimes smooth and sometimes covered with cilia.

Effect of Fright on Hair. — A Sepoy of the Bengal Army, brought as a
prisoner for examination before the British officers, was terribly affrighted,
trembled like a leafj and was almost stupified with fear. Such was the shock
upon his brain that his hair, from a glossy jet black, became gray within tho
space of an hour, the subject being only twenty- four years of age.

Also a boy, let down from a high cliff on the coast of Scotland to get ^^^^
of sea-birds. He, in defending himself from the birds with the sword, struck
the rope by which he was suspended, and cut off every strand but one.
When drawn up his hair was white.

Maria Antoinette experienced a change in the color of her hair during one
night's excessive fear.

CHAPTER SEVENTH.

THE INSTRUMENTS OE ANIMATION.— NEUROLOGY, OR
THE BRAIN AND NERVES.

DEFINITIONS AND DESCRIPTIONS.

562. Main Features of the Nervous System. — We
now come to an organization which is very complicated in
structure, some of whose functions are the most obscure of
any in the body. It is called the Nervous System : and the
different grades in the animal kingdom are established by
placing those having the most complicated nervous system
highest on the scale. Man having the largest brain in pro-
portion to the rest of his body, and possessed of the greatest
relative amount of nerves, is therefore placed at the head of
the animal kingdom.

563. Microscopic Structure. — Tubular Portion.— Diam-
eter of the Tubes, — In microscopic structure the nervous
tissue presents two essential elements : the fibrous or tubular,
which is mainly found in the nerve trunks, and the cellular or
vesicular, existing more abundantly in the ganglia or nerve
centers. In the former the tubes are the largest in the trunks
of the nerves, and gradually diminish as they approach the
brain, varying in size from the 2 oVoth to the ot^o oth of an
inch, and sometimes existing even as large as the 5 ioth of an
inch. They are sometimes conical also, measuring at one end
from jo'ooth of an inch to 24000th: the smallest end being
found near the nerve trunks, and are sometimes called coarse

562. Give the leading features of the nervous system. 663. What are the two inicro-
scopic elements of nervous tissue ? Give the size of the tubular portion.

AND PHYSIOLOGY.

Fig. 302.

817

Tubular Nerve Fibers.

nerve fibers. These fibers have the appearance of a double tube,
or a small tube within a larger one, and sometimes exhibit small
nucleated cells within the two.

564. A closer examination shows an inner or grayish por-
tion which is called the axis cylinder, and a ^vhite substance
around this called the medullary matter, or substance of
Schwan, and outside of the whole a membranous tube. (Fig.
302.) They are often called Fine Nerve Fibers. The sym-
pathetic system, on the other hand, seems to be made up of
tubes without this double structure, and when several of
them are joined in a bundle, they present a grayish appear-
ance. They are also of a much smaller size, varying mostly
from T50 ooth to u-oVoth of an inch.

565. Vesicular Structure . — The vesicular substance is
composed of cells or vesicles, which present very curious
forms, being somewhat stellate or caudate. The central por-
tion is globular, consisting of a nucleated cell, which sends
off processes in different directions, as seen in tlie annexed
Figure 303. Their diameter is exceedingly variable, meas-

What is the structure of the sympathetic system ? 5G4 What still more minute struc-
ture can be detected by the microscope ? 565. Describe the vesicular structure. Givo
the diameter of the cells.

318

HITCHCOCK'S ANATOMY

Fig. 303.

Vesicular Nerve Corpuscles, a. Cell "Wall. 7>. Cell Contents, c. Pigment, d. Nu-
cleus, e. Prolongation forming Sheath of the fiber. /. Nerve Fiber, magnified 350 diam-
eter.

Tiring from -.V.th

rth of an inch. These are found in

the ganglia and the substance of the brain.

5Q6. Divisions of the Nervous System. — The nervous
system consists of a central portion contained within the cav-
ity of the skull and the spinal column, and a great number
of white threads ramifying through every part of the body.
The physical condition upon •which the activity of the ner-
vous system depends, is the supply of arterial blood.

567. C c r 8l) r 11 III . — If we examine the parts within the skull,
(Fig. 804, f . 319,) we shall find the greater mass of it to be
of a spheroidal form, divided nearly into two halves by a deep
fissure or cleft, and its surface is singularly roughened by
elevations and depressions called anfractuosities.

588. This mass is the Cerebrum or Great Brain, and the
two divisions are called its hemispheres. (Fig. 307, p. 321.)

569. In man the average weight of the brain is fifty-four
ounces, in females forty-five; the maximum being sixty-four,

536. What principal divisions does the nervous system consist of? 567. Describe the
cerebrum. 569. What is the average weight of the brain ?

AND PHYSIOLOGY,

31 a

5''

Vertical Section of the Brain, Cerebellum, Pons Varolii, and Medulla Oblongata.
a. Anterior Lobe of the Brain, b. Middle Lobe, c, Posterior Lobe, d, Cerebellum, e, Me-
dulla Spinalis. /, Section of the Corpus Callosum. The Lateral Ventricles of the Brain
are situated on either side of the Corpus Callosum, which assists in forming their Upper
"Wall, ff, Optic Lobes : 1, Olfactory Nerves. 2, The Eyeball, from which may bo
traced the Optio Nervo as far as the Optic Thalami or Lobes. Close to this is the Kervo
of the Third Pair. 4, The Fourth Pair, distributed, like the Third, to the Muscles of the
Eyes. 5, Superior Maxillary Branch of the Fifth Pair. 5', Ophthalmic Branch of tho
same Pair of Nerves. 5", Inferior Maxillary Branch of the same Pair of Nerves. G, Sixth
Pair, proceeding to the Abducentes Muscle. 7, Facial Nerve : — under the origin of this
nerve may be seen a portion of the Acoustic 9, Nerve called Glosso-Pharyngeal. 10,
Pneumogastric Nerve ; close to it is 12, the Spinal Accessory. These three Nerves, tho
Glosso-Pharyngeal, Pneumogastric, and Spinal Accessory, are by some reckoned as ono
pair. 11, The Ninth Pair of some, and the Eleventh of others, called also Hypoglossal.
1-i and 15, Cervical Nerves.

and the minimum twenty ; the average capacity of the cra-
nia of Germans and Anglo-Saxons is ninety cubic inches.
Daniel "Webster's cranium contained 122 cubic inches.

570. Cerebellum. — The Cerebrum, by a band of thick
fibers, is connected with another body, of a pear shape, at-
tached to it by its base, called the Lesser Brain or Cerebel-
lum. (Fig. 306, p. 820.) This has about one eighth of the

state the average capacity of Anglo-Saxou crania, aJid al^o that of Daniel Webster.
570. Describe the cerebeUuin.

14*

320

HITCHCOCK'S ANATOMY

weight of the Cerebrum, and lies directly behind and be-
neath it.

Fig. 305. The Lateral Ventricles of tbo

Cercbruai. 1, 1, The Iavo Ilemi-
rphercs cut down to a level -with
the Corpus Callosnm, so as to
show the Centrum Ovale Majus.
The Surfiice is studded with tho
small Puncta Yiisculosa. 2, A
small portion of the Anterior Ex*
tremity of the Corpus Callosum.
3, Its Posterior Boundary ; the in-
termediate portion, forming tho
Eoof of the Lateral Ventricles, has
been removed so as to completely
expose these Cavities. 4, A part
of the Septum Lucidum, showing
a space between its Layers which
is the Fifth Ventricle. 5, The An-
terior Cornu of one Side. 6, Tho
commencement of the Middle
Cornu. 7, The Posterior Cornu.
8, The Corpus Striatum of one
A^entricle. 9, The Trenia Striata.
10, A small part of the Thalamus
Opticus. 11, The Plexus Cho-
roides. 12, Tho Fornix. 13, The
commencement of the Hippocam-
pus Major in the Middle Cornu. The Pounded Oblong Body in the Posterior Cornu
of the Lateral Ventricle, directly behind the Figure 13, is the Hippocampus Minor. A
Bristle is seen in the Foramen of Munro.

Fig. 306.

A View of tho Interior Surface of the Cerebellum and a Portion of tlje Medulla Ob-
lon:rata. 1, 1, The Circumference of the Cerebellum. 2,2, The two Hemispheres of the
Cerebellum. 3, Lobulus Amygdaloides. 4, Tho Vermis Inferior. 5, Lobulus Nervi
Pneumogastrici, C, The Calamus Scriptorius. 7, Its Point. S, Section of tho Medulla
Oblongata. 9, Points to tho Origin of the Pneumogastric Nerve.

AND PHYSIOLOGY

821

571. Cerebral Ganglia. — Also Ijing directly upon the
base of the brain, are found several distinct enlargements or

Fia. 307.

A Yiew of the Base of the Cerebrum and Cerebellum, together with their Nerves.
1, Anterior Extremity of the Fissure of the Hemispheres of the Brain. 2, Posterior Ex-
tremity of the same Fissure. 3, The Anterior Lobes of the Cerebruin. 4, Its Mid.Ilo
Lobe. 5, The Fissure of Sylvius. G, Tlie Posterior Lobe of the Cerebrum. 7, The,
Point of the Infundibulum. S, Its Body. 9, The Corpora Albicantia. 10, Cincritlr.s
Matter. 11, The Crura Cerebri. 12, Tlic Pons Varolii. 13, Tiic Top of tl:c Med.:];a
Oblongata. 14, Posterior Prolongation of the Pons Varolii. 15, Middle of tl:c C^^rib.'!-
Inm. IG, Anterior Part of the Cerebellum. 17, Its Posterior Part an. 1 the Fissure of itj
Hemispheres. IS, Superior Part of the Medulla Spinalis. 19, Middle Fissure of t'. 3
Medulla Oblongata. 20, The Corpus Pyramidale. 21, The Corpus Eestifornie. 22, Ti.j
Corpus Ollvare. 23, The Olfactory Nerve. 24, Its Bulb. 25, Its External Eoot. 23,
Its Middle Eoot 27, Its Internal Boot. 2S, The Optio Nervo beyond the Chiasm.
29, The Optic Nervo before tlic Chiasm. 30, The Motor Oculi. or Tidrd Pair <>f Nerves.
SI, The Fourth Pair, or Pathetic Nerves. 32, The Fifth Pair, or Trigeminus Nerves.
S3, The Sixth Pair, or Motor Externus. 34. The Facial Nerve. 35, The Anditn-y— tho
two making the Seventh Pair., S3, 37, 33, The Eighth Pair of Nerves. (The Ninth Paii-
arc not here seen.)-

5»i. 'What are the cerebral ganslia ?

322

H ITCH COCK

A N A T O M Y

ganglia, the most important of which are the Thalami Optici,
Corpora Striata, Olfactive Ganglia, and Tubercula Quadrige-

mma.

Fig. 308.

572. Spinal Cord. — Upon the an-
terior portion of the Cerebellum,
commences the Spinal Cord, the up-
per portion of which, situated within
the skull, is about three inches in
length and one in breadth, and is
called the Medulla Oblongata.

573. Cerebro-Spinal Center

These portions of the nervous sys-
tem constitute what is known as the
Cerebro-Spinal Axis or Center, and
are all made up of two kinds of mat-

The Cerebro-Spinal Axis seen Anteriorly. Tho
Nerves have been cut through at a short distance
from their Origin or central termination, a, The
Cerebrum. &, Anterior Lobe of the Left Hemisphere
of the Brain, c, Middle Lobe, c?, Posterior Lobe, al-
most concealed by the Cerebellum, e, The Cerebel-
lum, f, The Medulla Oblongata or Bulb. 1, First, or
Olfixctory Pair of Nerves. 2, Second Pair, or Optic.

8, Third Pair, or Motores Oculornm. 4, Fourth Pair,
or Pathetic. 5, The Facial, or Fifth Pair. 6, Sixth
Pair, or Abducentes. 7, Nerves of the Seventh Pair,
or Facial ; also the Acoustic, or Portio Mollis, by
some called the Auditory, and viewed as a division
of the Seventh ; others call them the Eighth Pair.

9, The Glosso-Pharyngeal Nerves, called the Ninth
Pair by some, by others the Anterior Division of tho
Eighth Pair. 10, The Pneumogastric, by some in-
cluded in the Eighth Pair, by others called the Tenth
Pair. 11, Nerves of the Eleventh and Twelfth Pairs,
the first being vievvcd by some as a Division of tho
Eighth Pair, and called Spinal Accessory ; the latter,
called by some the Ninth, by others the Twelfth, is

the Motor Nervo of tho Tongue. 13, Nerves of the Thirteenth Pair, or Sub-Occipital. 14,
15, IG, The First, Second, and Third Pairs of Cervical Nerves, ff. Cervical Nerves form-
ing the Brachial Plexus, 25, One of tho Pairs of Nerves of the Dorsal Portion of tho
Spinal Marrow, 33, One of tho Pairs of Lumbar Nerves, h. Lumbar and Sacral Nerves
forming tho Plexus whence come tho Nerves of tho Lower Extremities, i and J, Tor
minntion of tho Spinal Marrow, called Cauda Equina, k. Great Sciatic Nerve proceed*
ing to the Lower Extremities.

572. What is the medulla oblimgata ? 573. What two kinds of matter, does a slicing oi
tixe brain show, and how is the gray and white matter disposed?

AND PHYSIOLOGY

323.

ter ; the gray or external, and the white or internal. This
structure is best seen when the brain is cut through in a hori-
zontal direction; the gray showing itself as an outside layer
with an irregularly scolloped edge, while the white is internal,
and constitutes the greater portion of the whole brain.

t574. BIood-Yesseh of the Brain —Venous Sinuses,
• — The blood-vessels of the brain are very numerous, since one
sixth of all the blood is sent to this organ, although its weight
is about one fortieth of the body. The arteries are the most
numerous, and as already mentioned, those entering the head
from the front side of the neck, communicate very freely with
those coming in at the back side of the head, (see Fig. 213),
making a perfect circle of communication, so that there may
be no impediment to the cir-
culation of the blood through Fig. 309.
the nervous center. The veins
are not numerous. Some are
found on the surface of the
brain, but only a few pene-
trate into its substance. But
large channels are found be-
tween the membranes called
Sinuses, which do not pre-
sent the ordinary characteris-
tics of veins, except that they
convey the blood to the heart.
The two sinuses which are of
the largest size, discharge
their contents into the jugu-
lar veins. (Fig. 309.)

575. Membranes of the SmnsesoftheBaseoftheSkuIl. i,0ph-

CcrebrO-Spinal Center. — thalmic veins. 2, cavernous sinus. 8,

1» |.T . rp. Circular. 4, 6, Inferior Petrosal. 6, 9, Oc-

iJUra iUaiCr. inree mem- dpital sinuses. 7, I-nternaUugnlar vein.

574. What proportion of the blood- goes to the brain? Whicla are the most numerous,
the arteries or the veins ? What are the sinuses found there?

324 HITCHCOCK'S ANATOMY

branes envelop the brain, although to the unassisted eje they
appear as one. . Thej are of great importance in the economy
of the brain, and are often the seat of severe disease. The
outer one is called the Dura Ma1;er, that covers both the
brain and spinal cord, and is attached firmly to the bones
which it covers. It has the same composition as the liga-
ments of the body — white fibrous tissue — and consequently is
very tough, being the firmest of the three membranes.

576. Arachnoid MembiTiiic— The Arachnoid Membrane
lies directly beneath the dura mater, and receives its name
from the Greek word signifying spider's web.

577. Pia Mater.— Closely beneath it is the Pia Mater,
which lies directly upon the surfac3 of the brain, and dips
into all the cavities or convolutions on its surface. This
membrane is especially serviceable in the nourishment of the
brain, and receives the arteries which enter at the anterior
and posterior part of the skull. Its nerves are branches of
the sympathetic system.

578. Surface of the Brain . — The surface of the brain is
very uneven, being covered with convolutions or tortuous
ridges and corresponding depressions, the design of which is
not as yet well known, though probably merely to procure a
greater amount of surface, and they do not correspond to the
irregularities on the surface of the skull from which phre-
nologists profess to judge of character.

579. Ventricles of the Brain . — Within the brain are sev-
eral cavities called ventricles, of which the special use has not
been determined. (Fig. 805, p. 320.) It is a curious fact,
however, that a post mortem examination of the brain of in-
ebriates frequently discovers these cavities to be partially filled
with alcohol.

: 580. Division of the Nerves.— All the nerves that pro-

b75. IIow many membranes cnvelopiri'j: the brain? Describe the dura inn.' or, 576.
Describe the arachnoiil membrane. 577. Describe the pia mator. Wliat arc its nerves?
57S, What is tlie oonnition of tlie surface of the l)rain ? 579. What are the cavities, in tha
braia called ? 5S0. IIow are all the nerves given off from the braia and spinal cord ?

AND PHYSIOLOGY.

325'

ceed from the cerebro-spinal axis are given off in pairs on
opposite sides of the median line of the body. They are di-
vided into two sets ; those which are given off from the great
brain, little brain, and medulla oblongata, being called cranial
nerves^ and those from the spinal cord, sj^incd nerves.

581. Cranial Nerves. — Many of the cranial nerves, and
all of the spinal nerves, arise by two roots, and soon form a
small protuberance, which is called a Ganglion or knot, in
which the fibers are confusedly mixed together, after which
they proceed in the same sheath to their destination.

582. Of the cranial nerves there are twelve pairs, named
as follows :

First pair. .. .Olfactory.
Second "... .Optic.
Third "... .Motores Oculorum.
Fourth " ... .Trochleares.

Fifth " Trifacial.

Sixth " Abducentes.

Seventh pair . . Facial.
Eighth " ..Auditory.
Ninth " . .Glosso- Pharyngeal.
Tenth " . . Par Vagi.
Eleventh " .. Spinal Accessory.
Twelfth " ..Lincrual.

583. Olfactory. — The olfactory nerves arise from the an-

A View of the First Pair, or Olfactory, with the Nasal Branches of the Fifth. 1, Fronp
tal Sinus. 2, Sphenoidal Sinus. 8, Hard Palate. 4, Bulb of the Olfactory Nerve. 5,
Branches of the Olfactory on the Superior and Middle Turbinated Bones. 6, Spheno-
palatine Nerves from the Second of the Fifth. 7, Internal, Nasal Nerve from the First
of the Fifth. 6, Branches of Seven, to Schnoidorian Membrane. 9, Ganglion of Cloquet
jfl'tlie.fon'/mgntTi.cwisiifOTriD, Ahastoiriosis on the inferior Turbinated Bone of the
Branches of the Fifth Pair.

What are the two principal groups of nerves? 5S1. How many roots do most of tlio
nerves liavo ? 533. IIow many pairs of cranial nerves, and what are their naraea ?

326.

HITCHCOCK'S ANATOMY

Fig. 311.

terior portion of the base of the brain, and are distributed
upon the mucous membrane of the nostrils ; especially that
part of it which is spread out upon the turbinated bones.

584. Optic— The optic
nerves arise at a point be-
hind that where the olfac-
tories are given off, and
about one inch from this
point come together and
form a ganglion ; after this
they are again separated and
proceed to the posterior
portion of each eye-ball^
where they are expanded
into a membrane, called the
Ketina. (Fig. 311.)

585. Motores Oculonini.
— The tJm^d jj«ir are also
given off from the base of
the brain near to the pons
varolii, and are sent to a
part of the muscles of the
eye.

586. Troclileares.— The
trochlear es have nearly the
same origin as the last-men-
tioned pair, and are distrib-
uted to the superior oblique
muscles of each eye. (Fig.
312.)

587. Trifacial.— The fifth pair, or ^n/acm/, is the largest
of the cranial nerves. It is analogous to the spinal nerves in

A View of the Second Pair or Optic, and
the Origin of Seven other Pairs. 1, 1, Globe
of the Eye. The one on the left hand is per-
fect, but tiiat on the right lias the Sclerotic
and Choroid removed to show the Eetina. 2i
The Chiasm of the Optic Nerves. 3, The
Corpora Albicantia. 4, The Infundibiilum.
5, The Pons Varolii. 6, The Medulla Ob-
longata. The figure is on the Eight Corpus
Pyramidale. 7, The Tliird Pair, Motores
Oculi. 8, Fourth Pair, Pathetici. 9, Fifth
Pair, Trigemini. 10, Sixth Pair, Abducentes.
11, Seventh Pair, Auditory and F.acial. 12,
Eighth Pair, Pneumogastric, Spinal Acces-
sory, and Glosso-Pharyngeal. 13, Ninth Pair,
Hypoglossal

5S3. Give the anatomy of the olfactory nerves. 5S4. Describe the optic nerves. 555.
Describe the motores oculorum. -SSS. Give the anatomy of the fourth pair. 5ST. De«
Gcribe the tri£icial.

AND PHYSIOLOGY,

82>

Fig. 312.

A View of the Third, Fourth, and Sixth Pairs of Nerves. 1, Ball of the Eye, the Rec-
tus Externus Muscle being cut and hanging doAvn from its origin. 2, The Superior Max-
illa. 3, The Third Pair, or Motor Oculi, ^distributed to all the Muscles of the Eye except
the Superior Oblique and External Kectus. 4, The Fourth Pair, or Patheticus, going to
the Superior Oblique Muscle, 5, One of the Branches of the Fifth. G, The Sixth Pair,
or Motor Externus, distributed to the External Pectus Muscle. 7, Spheno-Palatino
Ganglion and Branches. 8, Ciliary Nerves from the Lenticular Ganglion, the short Eoot
of which is seen to connect it with the Third Pair,

Fig. 313.

A View of the Distribution of the Tri-
facial, or Fifth Pair. 1, Orbit. 2, Antrum
of Ilighmore. 3, Tongue. 4, Lower Max-
illa. 5, Eoot of Fifth Pair, forming the
Ganglion of Casser. G, First Branch, Oph-
thalmic. 7, Second Branch, Superior
Maxillary. 8, Third Branch, Inferior
Maxillary. 0, Frontal Branch, dividing
into External and Internal Frontal at 14.
10, Lachrymal branch, dividing before en-
tering the Lachrymal Gland. 11, Nasal
Branch. Just under the figure is the long
Eoot of the Lenticular or Ciliary Ganglion,
and a few of the Ciliary Nerves. 12, In-
ternal Nasal, disappearing through the
Anterior Ethmoidal Foramen. 13, Exter-
nal Nasal. 14, External and Internal
Frontal. 15, Infra-Orbitary Nerve. 16,
Posterior Dental Branches. 17, Middle
Dental Branch. 18, Anterior Dental
Nerve. 19, Terminating Branches of In-
fra-Orbital, called Labial and Palpebral.

20, Subcutaneous Mal?e,or Orbitar Branch.

21, Pterygoid or Eecurrent, from Meckel's
Ganglion. 22, Five Anterior Branches of
Third of Fiftli, being Nerves of Motion,
and called Masseter, Temporal, Ptergoid,
and Buccal, 23, Lingual Branch joined at an acute angle by the Chorda Tympani. 24,
Inferior Dental Nerve terminating in 25, Mental Branches. 26, Superficial Temporal
Nerve. 27, Auricular Branches. 28, Mylo-hyoid Branch.

328

HITCHCOCK'S ANATOMY

Fig. 314.

Distribution of the Fifth Pair of Nerves, a, Submaxillary Gland. 1, Small Eoot of
the Fifth Nerve. 2, Casserian Ganglion. 3, Ophthalmic Nerve. 4, Upper Maxillary
Nerve. 5, Lower Maxillary Nerve. G, Cliorda Tympani. 7, Facial Nerve.

that each nerve arises bj two roots, and afterwards, before
distribution, forms the Casserian ganglion. This ganglion is
separated into three branches : the ophthalmic, which supplies
^iG. 315. the region of the eje and

nose ; the superior maxil-
larj, supplying different
parts of the face from the
temporal muscle to the

A View of the Origin and Disiribu-
tion of the Portio Mollis of the Sev-
enth Pair, or Auditory Nerve. 1, The
Medulla Oblongata. 2, The Pons Var-
olii. 3, 4, The Crura Cerebelli of the
Eiglit Side. 5, Eighth Pair. 6, Ninth
Pair. 7, The Aii<litory Nerve distrib-
uted to the Cochlea and Labyrinth.
_ 8, The Sixth Pair. 9, The Portio Dura

of the Seventh Pair. 10, The Fourth Pair. 11, The Third Pair.

AND PHYSIOLOGY

m

lips, including the upper teeth
and the inferior maxillarj,
sending its branches to the
tongue, cheekss, and anterior
portion of the face.

588. Abdiiceiites. — The
sixth pair, abducent es, are sent
from the medulla oblongata to
the external muscle of the eje.

589. Facial,— The facial
nerves have their origin in
common with the last pair.
They join with some of the
branches of the fifth pair, and
distribute their filaments to
some of the muscles of the face.

590. Audi lory. —The aii-
ditory nerves^ as their names
imply, are sent to the ear.
They enter the internal ear

Origin and Distribution of the Tenth
Pair of Nerves. 1, 3, 4, The Medulla Ob-
longata. 1 Is the Corpus Pyramidale of
one side. 3, The Corpus Obi ivare. 4, Tho
Corpus Pvestiforme. 2, The Pons Varolii.
5, The Facial Nerve. 6, The Origin of tho
Glosso-Pharyngeal Nerve. 7, The Gang-
lion of Andersch. 8, The Trunk of tho
Nerve. 9, The Spinal Accessory Nerve.
10, The Ganglion of the Pneumogastric
Nerve. 11, Its Plexiform Ganglion. 12,
Its Trunk. 13, Its Pharyngeal Branch
forming the Pharyngeal Plexus (14), as-
sisted by a Branch from the Glosso-
pharyngeal (S), and one from tho Superior
Laryngeal Nerve (15). 16, Cardiac Branch-
es. 17, Recurrent Laryngeal Branch. 18,

Anterior Pulmonary Branches. 19, Posterior Pulmonary Branches. 20, Esophageal
Plexus. 21, Gastric Branches. 22, Origin of the Spinal Accessory Nerve. 23, Its
Branches distributed to the Sterno-Mastoid Muscle. 24, Its Branches to tho Trapezius
Muscle.

588. Describe the abducentes.
ditory nerves.

589. Describe the facial nerves. 590. Describe the au-

330

HITCHCOCK'S ANATOMY

after receiving fibers from the facial, and there divide into
two branches, which are distributed in the irregular labyrinth
of the ear.

591. Glosso-PIiaryngeal .—The glosso-pharyngeal makes
the ninth pair, and is sent to the mucous surface of the fauces,
tongue, tonsils, and mucous glands of the mouth.

592. Par Vagi, or P n e u m o g a s t r i c .—The tenth pair, 7?ar
vagum^ spring from the medulla oblongata, and after giv-
ing branches to several of
the cranial nerves, are dis-
tributed upon the heart,
lungs, stomach, and nearly
all the organs of the tho-
rax and abdomen.

593. Spinal Accessory.
— The spinal accessory

Fig. 31*7.

takes its

from the

The Anatomy of the side of the Neck,
showing the Nerves of the Tongue. 1,
A Fragment of the Temporal Bone
containing the Meatus Auclitorius Ex-
ternus, Mastoid, and Styloid Process.
2, The Stylo-Hyoid Muscle. 3, The
Stylo-Glossus. 4, The Stylo-Pharyn-
geus. 5, Tiie Tongue. 6, The llyo-
Glossus Muscle ; its two portions. 7,
The Genio-IIyo-Glossus Muscle. 8,
The Genio-llyoideus: they both arise
from the inner surface of the Symphy-
sis of the Lower Jaw. 9, The Sterno-
Hyoid Muscle. 10, The Sterno-Thyroid. 11, The Thyro-Hyoid, upon which the Thyro-
Hyoidean Branch of the Hypoglossal Nerve is seen ramifying. 12, The Omo-Hyoid
crossing the Common Carotid Artery (13), and Internal Jugular Vein (14). 15, The Ex-
ternal Carotid giving off its Branches. 16, The Internal Carotid. 17, The Gustatory
Nerve giving off a Branch to the Submaxillary Ganglion (18), and communicating a little
further on with tne Hypoglossal Nerve. 19, The Submaxillary, or Wharton's Duct,
passing forwards to the Sublingual Gland. 20, The Glosso-Pharyngeal Nerve, passing in
behind the Hyo-Glossus Muscle. 21. The Hypoglossal Nerve curving around the Oc-
cipital Artery. 22, The Descendens Noni Nerve, forming a Loop with (28) the Commu-
nicans Noni, which is seen to be arising by filaments from the Upper Cervical Nerves.
24, The Pncuinogastric Nerve, emerging from between the Internal Jugular Vein and
Common Carotid Artery, and entering the Chest. 25, The Facial Nerve, emerging fro!u
the Stylo-Mastoid Foramen, and crossing the External Carotid Artery.

Describe the glosso-pharyngeal, par vagum, and spinal accessory.

AND PHYSIOLOGY. 331

upper part of the spinal column, and afterwards enters the
cranium. After keeping company with the par vagum for a
part of its course, it is distributed to some of the muscles upon
the head and face.

594. Lingual. — The lingual nerve plunges its branches
deeply into the fibers of the tongue, and communicates with a
branch of the trifacial.

Fig 318.

595. Spinal Cord.— The sjnnal cord ct.

is that portion of the cerebro-spinal axis T ^

contained within the channel made by kE""

the foramina, or openings of the verte- ^^""'^

bra. It extends from the medulla ob- ^r^iV

longata just at the base of the skull, to \ \^

the second lumbar vertebra, and has an ^ /
average diameter of half an inch. It portion of the spinaicord

o and Ongin of one Pair of

has the general appearance of a flattened Nerves. «, spinai cord. 6,

11, T . . • 'i Posterior Eoot. c, Ganglion.

cord, but on a closer mSpeCtlOn it ap- ,?, Anterior Eoot. e, Trunk

pears to be made up of two smaller cords, formed by both. /, Branch,
called the lateral cords, nearly separated by two clefts, called
the anterior and posterior median fissures. This cord is not
perfectly uniform in its size, but presents two enlargements,
one at the point where the nerves are given ofi* to the upper
extremities, and the other near the lower end of the cord.

596. Microscopic Structure of the Spinal Cord.— In
anatomical structure we find the spinal cord and spinal nerves
are made up of two kinds of nervous matter, the white and
the gray, and also that each pair of these nerves arises by
an anterior and a posterior root. The posterior root is made
up of gray nervous tissue, and is called the sensitive root,
since it gives the sense of feeling to the parts where it is dis-
tributed ; the anterior root of white fibers is called the mo-
tor root, because it imparts motion to the diiferent muscles of

594. Describe the lingual. 595. What is the spinal cord ? Uow many fissures has the
spinal cord ? How many enlargements ? 596. What is the microscopic structure of the
spinal cord? Which is the sensitive and which the motor root?

332

HITCHCOCK'S ANATOMY

the bodj. A ganglion is found upon the posterior root, just
before it unites with the anterior.

59T. Origin of tlie Spinal N e r t e s .—Between each of
the vertebrae the spinal nerves are givenoff. These are made
up of fasciculi, and each fasciculus of distinct fibers which
somewhat resemble muscular fiber. They arise on each side
of the cord bj two roots, one given off from the anterior and
the other from the posterior part of the lateral cords ; the
anterior root being the one that is designed to produce mo-
tion, and the posterior giving sensation to the parts on which
it is distributed. These tw^o roots unite as soon as they have
fairly left the spinal cord, after which they proceed as a single
nerve. (See Fig. 318.)

598. Groups of Spinal Nerves.— These
nerves are grouped together, and have
the same name as the groups of verte-
brae in which they are located.

Fig. 319.

8 Cervical.
12 Dorsal.

5 Lumbar.

6 Sacral.

The last nine are additional, or supple-
mentary to the spinal cord, and not prop-
erly a portion of it. They are called
the Cauda equina.

599. Plexuses . — Most of these nerves
are grouped together soon after leaving
the spinal column, each group being
called a plexus (from the Greek " to
weave"), which is simply a net- work of
nervous fibers. Although there is to the naked eye a com-
plete interlacement and an apparent loss of fiber, yet by the
microscope these fibers can be distinctly traced through the
whole mass, with the exception of a few which are inter-
changed for purposes to be described hereafter. After emerg-

Diagram to show the De-
cussation (crossing from
side lo side) of Nerve Fi-
bers in a Nerve.

5£7. Give the oridn of the spinal nerves. 598. State the groups of the spinal nerves.
599. Describe the nature of the plexuses.

AND PHYSIOLOGY

Fig. 320.

333

Nervous System.
a, Brain. &, Little Brain, c, Spinal Marrow, d. Facial Nerve, e, Brachial Ploxus,
caused by the union of several Nerves coming from the Spinal Marrow, f. Median Nerve.
{7,- Cubital Nerve, /i, Internal Cutaneous Norve of the Arm. i. Radial and Musculo-
cutaneous Nerve of the Arra. j, Interco.stul Nerves, ky Femoral Plexus. ■ i, Sciatio
Plexus, m. Tibial Nerve, n, Eiternal Peroneal Nerve ; o. External Saphenous Nerves.

S34

HITCHCOCK'S ANATOMY

ing from the plexuses, the nerves proceed to their destination
and receive names, many of which are the same as the arteries
which they accompany.

600. Cervical Plexus — Brachial Plexus — Lumbar
Plexus — Sacral Plexus . — The cervical plexus is made up of
the four upper cervical nerves, and the brachial plexus of the

Fig. 321. Fig. 322.

A View of the Bracliial Plexus of Nerves and
Branches of Ann. 1, 1, The Scalenus Anticus Mus-
cle, In front of which are the Eoots of the Plexus.
2, 2, The Median Nerve. 3, The Ulnar Nerve. 4, Nerves of Front of Fore Arm 1,

The Branch to the Biceps Muscle. 5, The Nerves Median Nerve. 2, Anterior Branch
of Wrisbersr. 6, The Phrenic Nerve from the of Musculo-Spiral or Radial Nerve.
Third and Fourth Cervical. 8, Ulnar Nerve. 4, Division of Me-

dian Nerve in the Palm to the
Tliumb, First, Second, and Radial Side of Third Finger. 5, Division of Ulnar
Nerve to Ulnar Side of Third and both Sides of Fourth Finger.

600. What nerves gs to make up the cervical and brachial plexus ?

AND PHYSIOLOGY.

835

four lower cervical and upper dorsal nerves, and tliey give off
their branches to the upper part of the bodj. The lumbar
plexus is made up of the last dorsal nerve and the five lumbar
nerves ; and the sacral plexus of a branch of the last lumbar
and the upper sacral nerves. These supply the portions of
the body below the loins, and the superficial parts of the body
between the loins and upper part of the chest.

Fig. 323. Fig. 324.

A View of the Branches of the Ischiatla
Plexus to the Hip and Back of the Thigh.
1, 1, Posterior Sacral Nerves. 2, Nervi
Glutei. 3, The Internal Pudic Nerve
(Nervus Pudcndalis Longus Superior). 4,
The Lesser Isohiatic Nerve, giving off the
Perineal Cutaneous (Pudendalis Longus
Inferior), and 5, The Earnus Femoralla
Cutaneous Posterior. The reference to tho
Great Ischiatlc has been omitted. It la
seen to the right of 8.

A View of the Anterior Crural Ncrvo
and Branches. 1, Place of emergence of the Nerve under Pouparl's Ligament. 2,
Division of tho Nerve into Branches. 3, Femoral Artery. 4, Femoral Vein. 5,
Branches of Obturator Nerve. 6, Nervus Saphenus.

Describe the lumbar and sacral plexua.
15

336

HITCHCOCK'S ANATOMY

601. Direction of tlic Nerves. — The largest and most im-
portant nerves follow the same general direction as the larger
blood-vessels, and generally are in close proximity to them.

602. Motor Nerves — Mode of Termination — Pacinian
Corpuscles. — The nerve fibers which go from the anterior
columns of the spinal cord terminate in the fleshy portions of
the muscles, because they are the motor nerves, or those ex^

Fig. 325.

Fig. 326

A View of tlio Termination of
the Posterior Tibial Nerve in tho
Sole of the Foot. 1, Inside of the
Foot. 2, Outer Side. 3, Heel. 4,
Internal Plantar Nerve. 5, Exter-
nal Plantar Nerve. G, Branch to
Flexor Erevis. 7, Cianch to Out-
side of Little Toe. 8, Branch to

Space between Fourth and Fifth Toes. 9, 9, 9, Digital Branches to remainins
Opacos. 10, Branch to Internal Sido of Great Toe.

Pacinian Corpuscles. A, Single Corpusclo
highly Magnified. «, Its Peduncle. &, Its Nervo
Fiber, c, Outer Layers, and <f, Inner Layers of
the Capsule, f, Nerve Fibers, and /, Its Subdi-
vision and Termination. B, Portion of Digital
Nerves, M-ith Pacinian Corpuscles attached.

COl. Give the general direction of lU
motor nerves texmioate ?

nefvea through the body. 6Q2. W^bere do the

- AXD PHYSIOLOGY. SC?

citing motion. Those from the posterior columns spread
through the surface of the body, giving sensation to the skin.
The mode, however, in which they terminate is not always the
same. As far as at present is known, they seldom terminate
in a free or single extremity, but in loops, returning into
themselves, or joining with other fibers. And it is an an-
atomical fact that the nerve tubes do not anastomose one
with the other, as is the case among the blood-vessels ; but
each tube discharges its own duty, and not that of another
under any circumstances. In the skin of the hand and
foot they terminate in minute oval bodies from the risth to
the TTTrth of an inch in length, and from one twenty-sixth to
one twentieth of an inch in breadth, called Pacinian Cor-
puscles (from Pacini, their discoverer), and are attached to
the branches and extremities of the nerves very much in the
same manner as some kinds of fruit are attached to their
boughs. (Fig. 326.) Of these, there are about six hundred
in the hand and a somewhat smaller number in the foot; They
are composed of connective or areolar tissue in from twenty
to sixty bands, with interspaces containing a serous fluid, and
are attached to their nervous twig by a rounded peduncle.
The function of these bodies is entirely unknown.

603. Sympathetic System ^ Its Size — Connection
with Spinal Nerves — Destination of its Branches.—
Besides the cerebro- spinal center, there is another organi-
zation of nervous tissue which is called the Sympathetic
Nerve, or Ganglionic System, and is to be regarded as an
appendage of the spinal nerves. It is of very limited size,
consisting of mere reddish threads of nervous matter and oval
bodies called ganglia, never so large as peas. These ganglia
and nerves extend along each side of the spinal column from

State the manner In which they terminate. Give a description of th« Pacinian cor*
powlea. fioa. 1?lrhat la said 6f tba strttctore of the sjrmpathetie system ?

338

HITCHCOCK'S ANATOMY

Fig. 327.

tjjm. 8i, Globo of the Eye.

the atlas to the coccyx,
communicating with all
the spinal nerves by two
small fibers (see Fig.
328), and giving branches
to all the internal organs
and viscera. Branches
and ganglia are also
found between the bones
of the cranium and the
face. Tiie branches
which are given off to the
internal organs accom-
pany the arteries to the
same, forming a net-work

Great Sympathetic Nervo. 1,
Plexus on thti Carotid Artery in tho
Carotid Foramen. 2, Sixth Nerve
(Motor Externus). 3, First Branch
of the Fifth, or Oplithalmio Nerve.
4, A Branch on the Septum Narium
going to the Incisive Foramen. 5,
Recurrent Branch, or Vidian Nerve
dividing into the Carotid and Petro-
sal Branches. 6, Posterior Pahitino
Branches. 7, Lingual Nerve joined
by the Chorda Tympani. 8, Portio
Dura of the Seventh Pair. 9. Supe-
rior Cervical Ganglion. 10, Middle
Cervical Ganglion. 11, Inferior Cer-
vical Ganglion. 12, Eoots of tho
Great Splanchnic Nerve arising from
the Dorsal Ganglia. 13, Lesser
Splanchnic Nerve. 14. Eenal Plexus.
15, Solar Plexus. 10, Mesenteric
Plexus. IT, Lumbar Gan-lia. IS.
Sacral Ganglia. 19, Vesical Plexus.
20, Eectal Plexus. 21, Lumbar
Plexus (Cerebro-Spinal). 22, Eec-
tum. 23, Bladder. 24, Pubis. 25,
Crestof tho Ilium. 26, Kidney. 27,
Aorta. 28, Diaphragm. 29, Ileart.
SO, Larynx. 81, Submnxillary GJand.
82. Incisor Teeth. 83, Nasal Sep-
85, 86, Cavity of tho Cranium.

Whero docsit give Its bninches?

AND PHYSIOLOGY.

Fig. 328.

339

Hoots of a Dorsal Spinal Nerve, and its union with the Sympathetic.

c,c, Anterior Fissure of the Spinal Cord, o. Anterior Root, p, Posterior Root, with
its Ganglion. «', Anterior Branch, p'. Posterior Branch. «, Sympathetic. 6, Its
Double Junction with the Anterior Branch of the Spinal Nerve by a Wliite and Gray
Filament.

of communication around the vessels. And as all the inter-
nal organs, especially those called vital, are supplied with this
nerve, and not directly from the cerebro-spinal center, it is
hence called a nerve of organic life.

604. Sympathetic Ganglia.— Each of these ganglia may
be considered as a nervous center sending forth strands in
three directions ; 1st, to join the spinal nerves in their dis-
tribution ; 2d, to the spinal cord itself ; 3d, to the next sym-
pathetic ganglion above.

604. "What may each of these ganglia bo considered as ?

840 HITCHCOCK'S ANATOMY

605. Groups of Sympathetic G a n g 1 i a .—These ganglia
are grouped together according to the locality, to which their
branches are distributed. Thus we have the Cranial ganglia,
Cervical ganglia. Thoracic ganglia. Lumbar ganglia, and
Sacral ganglia. Besides these there are several large plex-
uses which have received distinct names, although a great
number of small ones have not received any names. Of the
most important ones we may name the Pharyngeal, in the
immediate vicinity of the Pharynx, the Cardiac lying upon
the heart, and the Solar, between the liver and stomach, or,
as is more commonly known, the pit of the stomach.

606. The Solar Plexus.— The Solar Plexus seems to be,
as its name implies, a sun or center for nervous power to the
intestines, since branches from this plexus accompany the ar-
teries to the vital organs, where they subdivide again and
again, and enter their coats and substance.

rUNCTIONS OF THE NEEVOUS SYSTEM

607. The functions of the Nervous System are the most
important and delicate of any in the body. 1. The Brain
affords a seat and center for life and intellect. 2. The nerves
are inlets for all the senses to the sensorium or seat of sensa-
tion. 3. They are the medium of all the movements of the
body, voluntary and involuntary. , 4. They establish and
maintain a sympathy between all the parts of the body, and
equalize all the vital forces. 5. They preside over the in-
voluntary functions, such as the circulation of the blood, di-
gestion, respiration, and reflex actions.

608. Intellect and Will located in the Brain.—
Voluntary Movements dependent on the Brain. —
The whole Brain not essential. — The Intellect and

CV>. IIow are the sympathetic g;in;,'',ia grouped together? AVhat is said of the sym-
pathetic plexuses? 606. Describe the solar plexus. 607. What are the five principal func-
tions of the nervous system ?

AND PHYSIOLOGY. 341'

Will evidently reside in the brain (cerebrum), and re-
quire that this organ should be in a healthy state, since,
if any disease aifects its whole substance, their power is
destroyed. Voluntary muscular movements depend on a
sound and healthy brain, although reflex movements, and the
motion necessary to sustain animal life, are often carried
on in some animals for a considerable time, when they are
born without a brain. But the whole brain does not seem to
be absolutely essential to life and mental operations, for many
instances are mentioned, where a considerable portion of the
brain has been removed by accident, such as a bullet or iron
bar being shot through the head followed by a discharge
of nervous matter : and yet the persons have lived for
years subsequent to the accident in as sound a condition as
ever.

608a. Necessity of two Cerebral Hemispheres.— One
may be injured, and not the other. — The reason of the
division of the brain into lobes or hemispheres is not so easily
understood. Perhaps it may be that so large an organ of so
soft a substance could not easily sustain its own weight, es-
pecially when reclined on one side, and at the same time
properly perform its functions. A more probable reason,
however, is this. It is a well-known fact, that one of the
hemispheres may be diseased or injured, so as to perform its
functions imperfectly, and yet the other hemisphere be in its
ordinary healthy state. Also, one hemisphere may be so
much affected, that the opposite side of the whole body is
paralyzed in motion or sensation, or both. It then seems
reasonable to suppose, that, since the brain would be so liable
to injuries, it was made in two portions, so as to prevent the
entire destruction of life by an injury to one of the hemi-
spheres.

60S. Where arc the intellect and the will located ? What movements depend on tho
brain? Is the whole brain absolutely essential for intellection ? COS a. Why arc thcra
probably two hemispheres to the brain?

S42 n ITCH COCK'S anatomy

609. To secure Precision in all Voluntary Actions.
—In Draper's Physiology is found another hypothesis for the
division of the brain into two parts : this is to secure precision
in the efforts of the intellect and will. ''For there is no
doubt," he says, "that the hemispheres have not only the
power of acting separately, but also conjointly ; thus there is
no student but must have observed, when busily engaged in
I'oading, that his mind will wander off to other things, though
liQ may mechanically cast his eye over page after page ; and
the same may occur in listening to a lecture or sermon. But
though the insane man may indulge in two synchronous trains
of thought, he never indulges in three, for the simple reason
that he has not three hemispheres to do it with, the same re-
mark applying to the sane man in the accidental v/andering
of his thoughts."

GIO. TliongM, Memory, and the Reasoning Powers
require a Sound Brain. — As already mentioned, the brain
is not the seat of motive power : this does not originate here,
although voluntary movements are controlled by it. But
automatic or reflex movements, such as the twitching of the
muscles of the leg and foot, when the sole of the foot is
tickled with some slightly irritating substance,' are entirely
beyond the control of the cerebrum or will, since they take
place nearly as well in a person who is asleep or stunned by
a blow, or even when the nerves of sensation and motion are
paralyzed. Thought, memory, reasoning, and all the intel-
lectual states demand a healthy and a sound brain for their
perfect action, while the ordinary muscular movements and
the functions of respiration, circulation, and digestion, are
dependent upon the Spinal Cord, Sympathetic Nerve, and
Cerebellum.

611. Definition of Sleep.— Need of Sleep. — Sleep,
'■tired nature's sweet restorer," is a state of the body, iii

coo. How can two hemisplieres secure a precision in voluntary actions ? 610. Are
reflex movements under tlie control of the brain ? What powers of mind are dependent
on the cerebrum ? »

AND PHYSIOLOGY. 843

wbich there is a more or less perfect suspension of the activ-
ity of the brain. The functions of digestion, secretion, and
respiration, proceed during the soundest sleep, though with
less activity than during the wakeful state. In many cases,
however, the functions of the brain do not entirely cease, as
is seen in the phenomena of dreaming, where the brain seems
to be actively at work, but the senses and animal functions
are quiescent. Sleep is demanded by all animals to procure
rest to the different organs of the body, and in health it comes
to all, though in different degrees of soundness, but generally
the greater the exhaustion, the more complete the sleep.

612. Periodical Tendency of Sleep.— The Will can
for some Time overcome Sleep. — The tendency to sleep
is periodical. All persons feel an inclination to sleep during
some portion of the twenty-four hours, and during the night,
if health be good and nature not perverted. Some strong
intellectual effort, however, or some powerful emotion, will
overcoms drowsiness for a long time, as in the case of the
student working out a difficult problem, or a mother w^atching
her sick child. But when the problem is mastered, and the
child has safely passed the crisis, sleep comes on with irresist-
ible force. Cases occur constantly to show that the brain
must have its repose in spite of intellectual effort or danger.
It is related that boys wearied out with continued labor in the
battle of the Nile, slept during a part of the action, and in
another naval engagement, a captain slept two hours within a
yard of his largest gun, which was kept in action during the
Avhole time. Indians at the stake of torture will sleep on the
least remission of agony, but awake as soon as it is renewed
again. And we learn that a most barbarous punishment is
still practiced in China, that of keeping a victim awake until
he dies of sheer exhaustion. The distress' of it is said to be
temblev -—- . ■

Gil. What is sleep? What powers aro inactive durin? sleep, and what processes are
carried on during it? What is sleep necessary for? 612. State the fact of a periodical
tendency to sleep. Can tha will overcoma sleep? For how lon^ a time ciu it do it?
-fielate the facts mentioned.

15*

^44 HI'TC II C OCR's ANATOMY

613. liiducemeiits to Sleep.— Sleep sometimes under
the Control of the Will, — 0 rdinaril j darkness and si-
lence promote sleep ; but if a person once becomes habituated
to noise during slumber — if it be a continuous one — he can
not sleep well without it. Thus persons living in the vicinity
of forges and noisj mills can not readily sleep elsewhere. And
a monotonous repetition of sounds is a most favorable provo-
cative to sleep, the cause of which is that other impressions
can not so readily be made on the mind, and thus the sleeper
is less easily roused. A dull reader on a dull subject has a
most ready effect in producing sleep, as well as the sound of
a distant waterfall, or the rustling of leaves in a forest. Rub-
bing many parts of the skin, or combing the hair by another
person, will often cause drowsiness, and sometimes sleep.
Again a person can sometimes put himself to sleep, if restless,
by a monotonous intellectual effort, such as the rehearsal of a
Latin paradigm, or counting the rain-drops, as they fall from
the eave trough into the spout.

614. Effect of Habit on Sleep.— The effect of habit is
powerful in producing sleep. Let one be accustomed to retire
early — in accordance with nature — and sleepiness comes at
the usual hour for retiring ; but if a person for a series of
years is in the habit of sleeping the latter part of the night
and early in the morning, it is almost impossible for him to
sleep early in the night. Those persons who, like sailors,
soldiers, and watchers, are obliged to catch sleep when they
can get it, and then only in small amounts at a time, sleep
with but little difficulty when the opportunity presents itself.
Captain Barclay, who walked one thousand miles in as many
consecutive hours, had such a power over himself, that he was
asleep the moment he lay down. Some physicians liave the
same power.

C18.- What arc the common -inducements to sleopj r>o any persons over •require a
noise, in order to sleop soundly ? What effect docs rubbing or chafinj? certain pai'ts of
tho body have upon sleep? Can sleep ever be brought about by an action of the will?
How ? C14. What clTect has habit upon producing sleep ? Mention the case of Captain
Ikurclay. '

AND PHYSIOLOGY. 345

615. Preventives of Sleep . — Any unusual noiso or place
of sleeping will prevent or disturb the sleep of many persons.
Thus the singing of a mosquito keeps many a man awake a
long time. But if a noise be repeated often, it will have
no effect of this kind. The college Freshman for the few first
mornings is readily awaked by the first stroke of the early
prayer-bell, but in a short time it has no effect whatever.
'• A gentleman who had taken his passage on board a man of
war, was aroused on the first morning by the report of the
morning gun, which chanced to be fired just above his head ;
the shock was so violent as to cause him to jump out of bed.
On the second morninsj he was aorain awakened, but this time
he merely started and sat up in bed ; on the third morning
the report had simply the effect of causing hira to open his
eyes for a moment and turn in his bed ; on tho fourth morn-
ing it ceased to affect him at all, and his slumbers continued
to be undisturbed so Ions; as ho remained on bo.ird."

61G. An Absence of Accustomed Sonnds prevents
Sleep. — The reverse of this sometimes happens, if there be a
cessation of monotonous and unaccustomed sound, by which
sleep was induced. Thus a person who has bean read or
preached to sleep, will awake if the reader or preacher pause
or stop, before any disturbance is made, and a person asleep
in a railway train, will often awake on the stopping, or even
on the slackening of the train.

617. Amount of Sleep. — The amount of sleep necessary
for man, varies exceedingly, being affected by the condition!
of age, temperament, habit, and exhaustion. Infants and
very old people sleep the most. The former require il that
the constructive process may go on as uninterru; tedly as
possible, and they generally sleep three fourths cf tbe time.
The latter need a large amount of sleep, because llie vital
energies are sp- feeble. ^ ' ' ' -

C15. What vrill often easily prevent sleep? Instance tlio collocro Freshman r.ml the
pentleman on the raan of wur. 616. IIow does an .absence of acciistomcil sDiiiuli affect
^sloop ? 617. Wliat amount of sleep is necessai-/ ? What ages sleep tlio mojt ?

346 HITCHCOCK'S ANATOMY

618. A Lynipliatic Temperament a Sleepy one. — Persons
of a lymphatic temperament, those who are seldom excited,
sleep more than those of a nervous temperament, who are
always rapid and quick in their movements. The former live
slowly, and but comparatively little waste is going on, and
consequently the brain is all the time nearer to sleep than in
the latter class, whose brain, when awake, is very active, and
"vyhen asleep, is asleep very soundly.

619. Effect of Habit on the Amount of Sleep.— Re-
markable Cases. — The amount of sleep is greatly modified
by habit, and often the briefest sleepers have been men of the
greatest activity. If a person acquire the habit of sleeping
but little, he must sleep very profoundly, so that w^hat is lost
in quantity, is made up in intensity. The habit of taking
but little sleep, however, is not a sure indication that a proper
amount of it has been secured. Frederic the Great, and
John Hunter slept but five hours out of the twenty-four ; and
General Elliot, engaged in the defense of Gibraltar, and Na-
poleon, often slept but four hours out of the twenty-four.
The general rule, however, seems to be that man should
take from six to eight hours of the twenty-four, for uninter-
rupted slumber. Women in general seem to require rather
more.

620. Mode of Access of Sleep. — To some deep comes on
instantly when the will determines upon it, but to others it is
a gradual and tedious process, especially in ill health, or an
excited mental state. Many physicians drop asleep as soon as
the head touches the pillow, and are aroused by no ordinary
sound, such as the tread of another person in the room, or
the shutting of a door, but wake as soon as the night-bell ia
rung. Sir E. Codrington, when a young man in the naval
service, was very active ?it oae time in looking out for signals,.

CIS. What aro the sleepy temperaments ^. What tho wido-iiwake ones? CI 9. How
does liabit affect tho amount of sleep ? State some remarkable bases. What is an avprago
amount of sleep for men? How mudi for-woaoen? 620. EjW does sleep come ou'»
Give exampiea.

AND PHYSIOLOGY. 34"?

and was employed during his waking hours in this business.
Hence his sleep was very solid, and he was roused by no or-
dinary sound, but his comrades amused themselves by whis-
pering the word "signal" in his ear, when he was at once
aroused and fit for duty.

621. Functions of the Cerebellum. — The Cerebellum
does not seem to be in any manner directly connected with
the phenomena of mind. But it seems designed simply for
the purpose of combining the actions of different muscles, or
presides over the coordination of voluntary muscular move-
ments, as in walking, speaking, and similar actions requiring
several sets of muscles to be used at the same instant. Ac-
cordingly in animals, which possess the greatest variety of
movements, we find the largest cerebellum.

622. Effects when Removed from Animals. — The Con-
trolling Power of Muscular Motions. — When this organ
has been removed from some of the lower animals, it was found
that they could not control their movements. When laid
down they could not recover their erect posture, and when
threatened with a blow, they in vain endeavored to avoid it.
Another phenomenon attending a wound, or removal of both
sides of the cerebellum, was the motion of the animal in a
backward direction, and the rolling from side to side on the
longitudinal axis of the body, and keeping up this motion
uninterruptedly, for several hours, at the rate of sixty revolu-
tions per minute. In some men who have been afflicted with
a disease of this organ, an unsteadiness of gait has been ob-
served, which gives additional strength to the belief that the
Cerehellimi is the regulator of tnuscular movements.

62S. Functions of the Medulla Ohlongata.— The Me-
dulla Oblongata seems to have for its function the sending of
nervous power to the muscles of respiration and swallowing^

621. Does tho cerebellum control the phenomena of mind? What aro its functions'
622. What effects does its removal causd in animals? How does a disease of it affiict
iDf Q ? 623. What operations are controlled by the medulla oblongata ?

348 HITCHCOCK'S ANATOMY

or, in other words, respiration and deglutition are controlled
and performed by the medulla oblongata.

624. Function of the Cerebral Ganglia. — The series of
Ganglia, Corpora stiiata, Thalami optici, etc., are regarded by
Dr. Carpenter as the true sensorium in man, and this is one
of the most important facts established with regard to the
nervous system. A prominent reason for the belief, that the
brain is simply superadded to them, is seen in many instances
of children born without a brain, but with the sensory ganglia
present, where the functions of animal life have been carried
on for a considerable length of time.

625. Functions of the Spinal Cord. — The functions of
the Spinal Cord are considered in a double aspect : First, as
the means of communication between the roots of the spinal
nerves, and those parts of the nervous system within the
cranium, and second, as a center of nervous power to pro-
duce reflex movements when an impression is made upon this
cord.

626. Function of Sympathetic Nerve.— The Sym-
pathetic Nerve '^in its offices is a motor nerve to many of the
internal viscera of the body, the heart and the intestinal canal
especially ; it is also a sensitive nerve to these parts, and it
presides over the action of the blood-vessels of these as well
as of the other parts, where it is distributed, as of the head
and neck, and likewise of all the principal glands of the
body."

627. Organic Functions depend on the Spinal Cord. —
Effect of Pressure on this Cord. — Almost all the func-
tions of organic life, such as breathing, digestion, and circu-
lation, are greatly influenced by the condition of the spinal
cord, and especially in its connection with the sympathetic
nerve, although the brain has some controlling power. Yet

624. By what set of bodies aro the principal functions of animal life carried on? 625,
^hat arc the functions of the s[iinal cord ? 633. Give the use of tho sympathetic nerve.
627. Upon what p<>rtions of the nervous system do orgaaio function* depend? •

AXD PHYSIOLOGY. 349

"when we are asleep, or the brain is stunned by a blow, the
organic functions are carried on as in the state of the activity
of the brain, though with far less energy. And in the case
already mentioned of animals born without a brain, life (or-
ganic) may. be sustained for a considerable time merely by the
functions of the spinal cord. If this cord be severed near the
head, or even if it be compressed, life soon ceases. This is
the manner in which death ensues by hanging, or breaking the
neck as it is termed ; where one vertebra is slipped from its
place (put out of joint), so that by the unequal contraction
of the muscles such a pressure is made on the cord that life
speedily becomes extinct. And if this cord is compressed in
any portion, sensibility and the power of motion in muscles
supplied by the part below the point of compression are de-
stroyed ; and if the pressure be long continued, or the cord
divided, its vitality is for ever destroyed, although the parts
above it are only indirectly affected.

628. Sensation Exists Previously to Motion— Centri-
petal and Centrifugal Fibers — Rate of Movement through
the Nerves. — From the fact that one portion of each nerve is
designed for sensation, and the other for motion, it is probable
that sensation must exist previous to the motion of the part.
Thus, for example, if the hand be brought in contact with any
substance without any previous knowledge of its presence, no
matter how soon the hand may seem to grasp it, yet the in-
terval must have been long enough for the sensation contact
to have passed from the hand to the brain, and the will to de-
termine upon the condition of the muscles, and the order to
pass down through the white fibers to the hand again before
the grasping can take place. Or the same thing may tala
place on receiving a shock, or series of shocks, from a gal-
vanic battery, the contrSxitions in this case being an instance
of involuntary or reflex movement. And although this fact

What is the effect of prcssura upon or division of the spinal cord? 628. What tvo
fiinoUuus e^ist in eodi serve ? Wbicli c:cists first, motioa or scoeation ?

350 HITCHCOCK'S ANATOMY

seems clearlj established, that one portion of each nerve trans-
mits the sensation to the brain, called the centripetal or sen-
sory, and the other conveys the order to the muscle, called the
centrifugal or motor, yet no anatomical difference can be de-
tected between the different fibers of the nerve. . From this
fact a German physiologist has made a series of curious cal-
culations, as a result of which he concludes that nervous in-
fluence, such as the will to move a certain muscle, travels at
the rate of 195 feet per second.

629. Ganglia Reservoirs of Power.— It has been sug-
gested, and with reason, that the ganglia, abundant as they are
in the body, act as reservoirs of nerve force, and the frequent
commissures, or union and subsequent divergence of nerve
fibers, is to draw off a part of the influence which is coming
along the centripetal fiber, and directing it into a new chan-
nel.

630. Divisions of the Cranial Nerves.— The cranial
nerves may be divided, according to their function, into three
groups :

Olfactory.

Special Sense ■{ Optic.

Auditory.

Motores Oculorum.
Patlieticus.
Abducentes.
Facial.
Lingual.
Trifacial,

Glosso-Ph aryngeal.
Par Yagum.
I Spinal Accessory.

631. The olfactory nerve is the one by which we gain the
smell of odoriferous substances, as they are brought in con-
tact with this nerve in the lining membrane of the nose.

What are tho centripetal and what the centrifnfal fibers Af the nerves?" What is 4
probablo rate at which the influence is transniitted through the nerves to and from tho
brain ? 629. What theory has been offered for the"nsTo7tireVaTTgiTa?~ 630.' What three
groups of tho cervical nerves are here given ? 631-640. State the function of each paii-
of the cranial nerves.

Motion.

Compound

AND PHYSIOLOGY. 351

632. The optic nerve, as expanded in the retina, is the
nerve of sight.

633. The auditory nerve receives the vibrations of the air,
which produce sound.

634. The motores oculorum, pathetici, and abducentes are
the nerves which furnish motive power to the eje-ball.

635. The facial nerve is distributed to the muscles of the
face, and is the one that aids in the expressions of the emo-
tions and will, as exhibited in the countenance. It is also the
channel of the reflex actions in respiration, as when a person
involuntarily gasps if cold water be dashed in the face.

636. The lingual (hypoglossal) nerve is necessary for the
production of articulate speech, regulating and controlling as
it does the muscles of the tongue.

637. The trifacial nerve administers the sense of touch to
the surface of the tongue, and aids somewhat in the sense of
taste. One branch of it is a muscular branch. Another is
sent to the mucous surface of the* eye, and if it be cut off the
eye is destroyed by suppuration.

638. The glosso-pharyngeal is the essential nerve of taste,
and is closely connected in function with the trifacial. It
seems also to be the nerve through which unpleasant sensa,-
tions excited in the mouth are conveyed to the medulla ob-
longata so as to excite nausea and vomiting.

639. The par vagum sends nervous power to the heart-
stomach, lungs, and larynx, as well as conveys to the braift
any disagreeable sensations excited in these organs. Conse-
quently this is the essential nerve of digestion, respiration,
circulation, and opening or closure of the glottis under ordi-
nary circumstances.

640. The spinal accessory seems to be the nerve by which
the regulation of the muscles essential to the production of
voice is effected.

352 HITCHCOCK'S ANATOMY

641. Use of Spinal Nerves. — The use of the Spinal
Nerves is to convey impressions made at the surface of the
body — including the extremities — to the brain, and to trans-
mit impulses to the muscles from the brain. Both of these
influences are transmitted by the same nerve or filament,
though in opposite directions. From carefully conducted ex-
periments it seems quite probable that the "coarse fibers"
transmit the impulses to the muscles, and are called afferent^
while the fine fibers conduct the impressions to the brain, and
are called efferent. And in the muscular nerves the coarse
fiber is proportioned to the fine as 10 : 3.3, while in the
trunk, as it issues from the spinal cord, it is in the ratio of
10 : 11.

HYGIENIC IXFEREITCES.

642. Tlic Nervous System not easily Diseased. — 1. It

is a singular fact that the nervous system, so delicate in its
organization and mysterious in many of its functions, is to
so small an extent dependent upon any particular rules for
the maintenance of its health, the main thing necessary for
its welfare being an attendance to the general health of the
body.

643. It needs Action. — 2. The nervous system, like all
other parts of the body, requires action for its health. If a
person has nothing upon which he can exert his nervous
energy, he is liable to disease ; and no class of people are so
subject to nervous diseases as the wealthy, who are obliged to
make little exertion to procure the necessaries and luxuries of
life. Hence we infer that employment of some kind is indis-
pensable to the health of the nervous system.

644. Sleep indispensable to its Health. — 3. This system

G41. What is the use of the spinal nerves? What is the difference in function between
the coarse and the fine fibers? 642. Is the nervous system easily aff^-cted by serious dis-
ease ? 643. What is the necessity of action to the nervous system ?

AND PHYSIOLOGY. 353

requires sound sleep. For this alone can return to the brain
its expended energies. It is as necessary to the brain as
steam to the locomotive. And no person can enjoy the per-
fection of health to old age, who does not gain a due supply
of sleep. Hence the very ambitious student, or the man eager
to make money, whose time, energies and thoughts are so
engrossed that he can not, or will not, find time to sleep, vio-
lates one of nature's principal laws, and sooner or later will
receive the penalty. And, according to insane hospital re-
ports, one of the principal causes of insanity is put down to a
want of sleep.

645. Needs Rest and Recreation. — 4. The mind not only
needs sleep, but also recreation or an occasional change of its
objects of thought. Long-continued trains of thought are to
the brain what working one set of muscles incessantly all day
is to them — complete exhaustion. He then that would last
the longest, must occasionally turn his thoughts from his or-
dinary avocation completely, and so give the brain rest. This
applies to every one, whether he is the business man, student,
or the hard-working farmer or mechanic. And every one
also needs a vacation, or at least some change of employment,
once or twice during the year, when, for a few weeks or days,
lie may break up the ordinary routine of life.

646. Necessity of various Objects for the Mind to di-
vert itself with. — 5. If change or recreation be so impor-
tant for the health, how necessary that the mind should have
various objects on which to employ itself when free from daily
duties. How pleasantly, and profitably, for instance, can
one pass his leisure hours, if he will but cultivate a taste
for music, reading, or some branch of natural history, as for
example zoology, botany, mineralogy, or geology ! These
pursuits not only give healthful physical recreation, but by

644. What is the effect of a want or scarcity of sleep ? What is often a prominent
cause of insanity? 645. What kind of rest does the mind need besides sleep? Do all
employments need a vacation ? C46. Is exercise, that is taken simply for exercise, ever
the best ? What studies combine profit as well as recreation and exercise ?

3M HITCHCOCK'S anatomy

the attractive and fascinating objects of study which they
offer, they divert the mind from the ordinary cares and trour
bles of life, and also exert a healthful moral influence. To
literary and professional men, as well as many of business
engagements, such a source of recreation and improvement is
of very groat importance, since often they are not interested
in many of the recreations and pleasures which divert the
great mass of society, and also because new thoughts and
means of illustration may be gained from them.

64T. The Brain must be worked Pliilosopliieally, not
Spasmodically. — 6. The brain and nervous system will per-
form more labor, if worked philosophically, than if worked
spasmodically. That is, mental and corporeal labor performed
regularly and steadily, and only up to the ordinary power of
the brain and nerves to sustain, will not wear away the ner-
vous system to such an extent as if it be performed by over^-
working for a few days and then lying idle.

648. Value of iilental Abstraction.— 7. As a general fact
the mind acting through the brain can not successfully work in
the midst of noise and external attractions. But by practice
many can engage in deep study and intense thought, even in
the company of those who are talking, laughing, singing, or
in the midst of any noise. This is a valuable acquisition and
one that should be sought after by every one, since all of us
are liable to be thrown into such circumstances, that we
must work, think, and transact business in noise and confu-
sion.

649. Tliebcst Time for Study.— 8. We see from this sub-
ject that the best time for study is in the morning, for then the
brain is rested, and can with the greatest vigor and alacrity
engage in its efforts. But here the fact presents itself, that
the morning is the best time for physical exercise, and to

647. How should the braia and nervous system bo worked ? 64S. What is said of tho
value of mental abstraction ? 649. What is the best time for study ?

AND PHTSIOLOaY. S55

which shall "sve give the preference ? Shall we deprive our
bodies of exercise, or shall we give up the best eflforts of the
brain ? Without hesitancy, as a general ruJe, we should
say, attend to the physical exercise first, for if the general
health be broken down, the brain will sympathize, and then
close mental effort will be at an end. Hence, although morn-
ing is the best time for study, yet we must not take the whole
of it for that purpose, but must share it with exercise. To a
student who is passing through a long course of study, early
rising and retiring, and generally exercise in the morning
before commencing study, will tend to preserve and invigorate
health. Studying late at night and sleeping long in the
morning, are injurious to no class of people more than to the
hard student.

650. Peniicious Effect of Tobacco on the Brain.— 9.

The effect of tobacco on the brain is thus described, in his
medical lectures, by Dr. Solly, an eminent physiologist and
practical physician: "I would caution you, as students,
fi-om excesses in the use of tobacco and smoking, and I would
advise you to disabuse your patients' minds of the idea that
it is harmless. I have had a large experience of brain dis-
ease, and am satisfied now that smoking is a most noxious
habit. I know of no cause or agent that tends so much to
bring on functional disease, and through this in the end to
lead to or^inic diseases of the brain, as excessive use of to-
bacco.''

651. Power of the Feelings over the Nervous Syst£m. —
10. It is wonderful and interesting to see what is the power
exDrted by the feelings and emotions upon the nervous sys-
tem, and through that upon the whole body. Let the farmer
feel that his severe labor is sure to bring him in good crops,
and how happily does he persevere in his severe toil month
after month. And if the merchant can only know that his

But how shall exercise and study both bo properly attended to ? What is said of early
rising? 650. How dops tobacco affect the braiu? 651. What effect have the emotion*
upon the physical system ?

356 HITCHCOCK'S ANATOMir

gains are great, how incessantly will he work day and night,
and jet consider his no hard life. But if there be no encour-
agement, no prospect of reward to the working-man in his
employment, what drudgery does it become ! In ay, how posi-
tively injurious to health and vigor of body and mind.

652. To the scholar, however, this principle is much more
important than to him who labors only with the muscles, since
these organs can be worked to a considerable extent with an
unwilling mind ; but to work a brain already depressed and
discouraged is much more diificult, and sure to bring on grave
disease. When the spirits are light and the mind free, the
memory can be more readily stored with facts and principles,
and the reasoning powers more easily developed. It is hence
the duty of teachers to make study as pleasant and attractive
as possible ; it becomes those who select the location and con-
struct the buildings of colleges, academies, and school-house?,
to have a reference to taste and comfort in their plans, so that
physical inconvenience may not render study irksome, and
that the taste of the student may be improved as much as pos-
sible by the construction and arrangements of these buildings.

653. Control of the Nervous System by Moral aKd
Religious Feelings.— 11. Finally, of all the sources and
promoters of health, correct moral and religious feelings and
principles are among the most powerful. The reaction of a
guilty conscience upon the body, in obstructing the functions
and in bringing on weakness and p emature decay, is well
known. Equally powerful in promoting health and longevity
is an approving conscience. A cheerful acquiescence in the
divine will has often done more to restore the invalid and
maintain good health against disease, than all medical reme-
dies ; while pure and ennobling sentiments and religious hopes
have sometimes been more efficacious to prolong life on earth
t'lan all other hygienic prescriptions.

652. What offt'Ct has plensurnblo. feelings on tho progress of the scholar? 658. State
tho valno of an approving conscience upoa all classes of society, as It simply respects
physical teulth.

AND PHYSIOLOGY.

35T

COMPARATIVE NEUROLOGY.

654. Among all the higher
mammals we are able to trace
nearly all the different parts
of the nervous system as they
are exhibited and arranged in
man, though many of them
are considerably modified.

655. Weight of Brains.—
The relative weight of the
brain is greater in the smaller
ani trials. Thus, in the mouse
it is said to be ^\d. the weight
of the body. In the elephant
the weiojht of the brain is

Fig.

Fig. 329.

Brain of Squirrel laid open. B, Cere-
brum. D, Cerebellum. C, Optic Lobes.
thai., Thalamus Opticus, c, «, Corpus
Striatum.

Upper and Under Surface of Brain oi Rablit, A, B, D, as b<»fore. ol, Olfactive Lobes.

op, Optic Nerve, mo. Motor Oculi. cm, Corpora Mamillaria. c, e, Crus Cerebri. pVy

Pons Varolii, pa, Patheticus. tri. Trifacial, ah, Abducens. /rtc. Facial, av, Audi'
tory. Tuor., Vagus. ^, Spinal Accessory. 7iyj9,, Hypoglossal.

655. What is said of the size of braias 5

B5^ HITCHCOCK'S ANATOMY

-g-ij^th the weight of the body; in the ox, ^Jo^h; in the fox,
^^jth; while in man it is ^'^th the weight of the body.

656. Proportion of the AVidtli of Brain and Spinal
Cord in Man and other Mammalia. — This, as well as the
comparison of cerebral mass and cerebral nerves, between man
and other animals, is interesting. The breadth of the spinal
marrow is, to that of the breadth of the brain, in man, as
1:7; in the dog, as 1 : 2.

657. Cerebral Nerves. — "The cerebral nerves correspond
to those of man. The first pair, however, forms in some de-
gree an exception, for though not absent in all the whale
family, it is wanting in the dolphins. In most mammals the
olfactory nerves are thick and have a cavity in them. The
fifth pair of nerves is, in many mammals, of peculiar strength
and thickness when compared with that pair in man."

658. Sympathetic System. — "The nervous system of
organic life— the great sympathetic — is formed, as far as in-
vestigations indicate, essentially as in man." It is situated
mostly in the cavities of the thorax and abdomen, and follows
the course of the blood vessels.

659. Tentorium.. — The tentorium cerebelli, which in man
is a simple tough membrane that separates the cerebrum from
the cerebellum, is very delicate in some animals, as the horse
and dolphin ; while in the cat it is supported by a bony plate
springing from the skull, and is a very firm membrane. Its
use to protect the brain in those animals whose movements
are at times violent and sudden, and especially those that leap
great distances.

660. Spinal Nerves. — The Spinal nerves also, in general
appearance, are like those in man. The number of pairs
varies in difierent species, as might be inferred from the dif-
fering, number of their vertebrae.

C5G. Slate the proportion of the width of-the brain and spinal cord. 65T. What is said
of the cerebral nerves of animals ? 658. What is said of the sympathetic system ? 659.
What is said of the tentorium ? €60. What of the spinal nerves of aninaala ?

AND THYSIOLOGY,

35d

661. Actual Proportion between Cerebrum and Cere-
bellum.— According to Cuvier, the proportion of the cere-
bellum to the cerebrum, by weight, in the baboon, is as
1:7; in the dog, 1:8; in the sheep, 1:5; and in the horse,
1:7.

662. Spinal Cord. — The essential difference between the
spinal cord in man and the lower mammalia, is its greater
length, and a narrow canal which runs longitudinally through
the middle of it.

663. Nervous System of Birds.— The brain of birds is
characterized by the smallness of the hemispheres, though
more fully developed than in

reptiles and fishes. In the
sparrow the weight of the
brain to the whole body is as
1 : 25 ; in the goose, 1 : 800 ;
and in the cassowary, 1 : 1000.
It is destitute of convolutions,
or in other words is perfectly
smooth on its surface, and has
laroje cavities or ventricles con-
tained in it : and, as in mam-
mals, the mass of the brain
is greater than that of the
spinal cord. The pairs of the cerebral nerves are the same
as in mammals ; also the principal divisions are the same.
The cerebellum, as in man, exhibits the arbor vitse when cut
through vertically.

664. Nervous System of Reptiles. — The brain of rep-

Brain of Buzzard. B, Cerebrum, C,
Optic Ganglia. D, Cerebellum, g, Pineal
Gland.

661. What is the proportion between the weight of the cerebrum and cerebellum in
some of the lower animals ? 662. What is the essential difference between the spinal cord
of man and that of most quadrupeds? 663. How is the brain of birds characterized?
Give some ef the proportional weights of it compared with that of the whole body f

10

360

HITCHCOCK'S ANATOMY

^i»- 332. tiles constitutes but a very

small part of the body. In
the frog the proportion to the
whole weight of the body is
as 1 : 172 ; in the Coluber
matrix (snake), 1 : 792 ; in a
turtle, 1 : 5688. The hemi-
spheres are smooth and hollow
internally. The optic lobes
are large in proportion to the
size of the eyes, and are hoi-,
low internally. The cerebel-
lum of frogs is merely a thin
plate of nervous matter.

665. Nervous System of
Fishes . — We find the lowest
development of the nervous
system among vertebrates in
the fishes. The brain here does not fill the whole cranial
cavity, so that between the brain and dura mater there is
found a quantity of loose cellular tissue, with which is inter-
spersed a fluid oil. The brain in weight does not equal that
of the spinal cord, nor is it but a little broader than the cord.
Its weight in proportion to that of the body is about y^'o o^th
part. It is composed of eight lobes, partly in pairs, and
partly unpaired behind one another, which seem to correspond
to the cerebellum (divided), corpora quadrigemina, thalami
optici, and medulla oblongata.

Q6Q. Electrical Organs in Fishes. — There are at least
seven species of fish that possess the power of giving electric
discharges. The organs which accomplish this in the Torpedo
are two large crescent-like bodies (see Fig. 334), which are

Brain of Turtle. A, Olfactive Ganglia.
B, Cerebrum. C, Optic Ganglia. D, Cere-
bellum.

664. What Is said of the brain of reptiles? State its comparative size with that of the
whole body. 665. State some of the peculiarities of the brain in fishes. What is its
relative, weiziit? 666. What Is said of the electrical organs of some fishes? Give the
anatomy of these organs.

AND PHYSIOLOGY.

Fig. 333.

361

m tjj

Brains of Fislies. A, Olfactive Lobes or Ganglia. B, Cerebral Hemispheres. C, Op«
tic Lobes. D, Cerebellum, ol, Olfactory Nerve, op, Optic Nerve, pa, Patheticus.
mo. Motor Oculi. ab, Abducens. tri, Trifacial, fa. Facial, aw, Auditory, vaff, Va«
gus. tt, Tubercles or Ganglia of the Trifacial, io, Tubercles of the Vagus.

made up of a large number of short, six-sided prisms, and
are abundantly supplied -with nerves. And as these organs
are made up of prisms, which stand end upon end, and not
side hj side only, as they appear in the cut, the idea seema

362

HITCHCOCK'S ANATOMY

Fig. 334.

Fig. 335.

Electrical Apparatus of Torpedo, b, Nervous System of an Articulate.

Brancliiae. c, Brain, e, Electric Organ.

ff, Cartilage of Cranium, me, Spinal Cord, n, Nerves to the Pectoral Fins, nl, Lat-
eral Nerves to the Body, np, Large Nerves (Pnoumogastric) to the Electric Organ.
o. Eye.

plausible that they may be regarded as Voltaic piles, or a
reservoir of electric power which the fish can discharge at
will. And it is necessary for the generation of this electrical
discharge that the integrity of the nervous system be main-
tained.

667. Nervous System in Articulata. — In the Crusta-
ceans the nervous system consists of ganglia and cords. The
central ganglion may be regarded as a brain, which sends off
nerves of vision, audition, feeling, and smelling. A splanch-
nic or sympathetic nerve is also found, as in the Arachnoidea
and Annelida. The two latter classes have ganglia, which

667. State the general plan of th© nervous system In articulates.

AND PHYSIOLOGY.

363

Fig. 336.

Nervous System of a Beetle.

may be called a brain. In
Insects ^' the central parts
of the nervous system con-
sist of a brain and a ven-
tral cord," as is shown on
'Fior. 336. In some of the

o

lower tribes of Articulates,
as the Helminthes and Rota-
toria, the nervous system
is feebly and indistinctly de-
veloped.

668. Reflex Actions in Ar-
ticulates.— This sub-king-
dom is remarkable for its reflex actions. Thus if the head of a
centipede be cut off while it is in motion, the body will con-
tinue to move by the action of its legs : and the same will
take place, if the body is divided into several segments. The
explanation is as follows. "The body is moved forward by
the regular and successive action of its legs, as in the natural
state : but its movements are always forwards, never back-
wards, and are only directed to one side, when the forward
movement is checked by an interposed obstacle. Hence, al-
though they might seem to indicate consciousness and a guid-
ing will, they do not so in reality : for they are carried on as
it were mechanically, and show no direction or object, no
avoidance of danger. If the body be opposed in its progress
by an object of not more than half its height, it mounts over
it, and moves directly onwards, as in its natural state : but if
tlie obstacle be equal to its own height, its progress is ar-
rested, and the cut extremity of the body remains forced up
against the opposing substance, the legs still continuing to
move J ^

What is the name of the principal ganglia? 668. What is said of the reflex actions
of articulate animals ? What are these reflex actions sometimes mistaken for s Give
the example.

364

HITCHCOCK'S ANATOMY

669. Nervous System of Molluscs.— Cephalic Gang-
lia.—Pedal Ganglia.— Parieto-Splanchnic Ganglia.
— Ir. most of the Molluscs the nervous system is well de-

FiG. 337.
A

"ferrous System of Argonauta Argo. A, As seen in front. B, As viewed in profile,
•fihowing the relations of the Nervous Centers to the Buccal Mass. A, The Esophagus B,
and the Eyo c. a. Cephalic Ganglion. 6, Buccal Ganglion, c, Sub-Esophageal Gang-
lion, d, d. Stellate Ganglia of the Mantle, e, Visceral Ganglion. / Nerves of the
Arms, with Ganglionic Enlargements, g, Optic Nerves, h, h, Eyes. *, i, Brijnchial
Nerves with their Ganglia.

AND PHYSIOLOGY. 365

veloped; the most so in the Cephalopods, which are the
highest in organization. In these we find a central organ
quite like a brain, enveloped bj a membrane analogous to
the Dura Mater. This system is shown on Fig. 337. The
general arrangement is that of three principal pairs of ganglia
with nerves proceeding from them. The first pair is called
the Cephalic ganglia, which is the largest, and is located
above or on the sides of the esophagus, with a collar of nerves
surrounding that tube. This gives off nerves to the organs
of vision and taste, and to the muscular apparatus of the mouth.
The second pair, called the Pedal ganglia, is located beneath
the esophagus, giving off nerves to the foot and the organs of
hearing, when thi3 sense is not actually located in the foot.
The third pair, the Parieto- Splanchnic ganglia, are usually
found in the posterior part of the body giving nerves to the
muscular and sensitive walls of the body, the respiratory ap-
paratus, the heart and large blood vessels.

670. Nervous System of Radiates.— Need of a Nerv-
ous System. — Among the higher Radiates a nervous system
of inferior organization can be found. For the most part it
consists of a ring of nervous Fi^ 33 s.

matter about the mouth,
which sends off branches in
different directions. " In
Medusae the nervous system
consists of a simple cord, of
a string of ovate cells, form-
ing a ring aroung the lower
margin of the animal." — „ ,«. r-i

° Nervous System of Star-Fish, gr, gr, Live

Agassiz. (Fig. 338.) Gang- oangua.

lia, or reservoirs of force can but seldom be found.

671. Among the Infusoria no nervous system can be de-
tected, and if any exist, its participation in the general course

669. What is the principal arrangement of the nervous system among moUuscs? 6T0.
What is the nervous system of the radiates ? 6TI. How is the nervous system among
Eadiates?

806 HITCHCOCK'S ANATOMY

of A^tal action must be ver j trifling. For the simplest office
of a nervous sjstem is to establish a communication between
the different parts of the body ; but if every part of the body
has similar endowments, there can be no object in such com-
munication. For instance, where every part of the surface —
as is the case in those animals — is equally susceptible of ab-
Borption, there can be no need of a circulating system, and
where contractility seems to be diffused through the body
alike, a nervous system would be superfluous.

671. What of the nervous BjBtem of Infoaorlik

CHAPTER EIGHTH.

THE INLETS TO THE SOUL.— THE SENSES.

ENERAL REMARKS.

672. The Senses.— Dependent on the Mind. — These are
commonly known under the name of senses. Five are usually
reckoned, Seeing, Hearing, Tasting, Feeling, and Smelling;
and it is by these alone that we are made acquainted with ex-
ternal objects. In other words, sensation may be defined as
the consciousness of impressions. The mind, for aught we
know, might be able to carry on its functions of thinking,
reasoning, and memory, and also be conscious of its own ex-
istence, if it were deprived of the senses : but it could not
make itself felt on other minds, nor increase in knowledge and
discipline without their aid. And although the primary ob-
ject of the senses is to promote physical enjoyment, yet their
highest and noblest use is to subserve the purposes of the
mind.

673. Senses best Developed in Lower Animals. — In
man the senses are not so fully developed as in most of the
lower animals. But this deficiency is much more than com-
pensated by the superiority of his intellect.

674. Effect of excessive Use of the S e n s e s .—Excessive
indulgence of any of the senses is apt to produce painful in-
stead of pleasurable sensations. Thus heat of a moderate

6T2. Whnt are the inlets of the soul ? Is mind necessary for the existence of sense ?
"What is the primary use of the senses? What should bo their hishest us3? 673. In
-what animals are tlie senses the most perfectly developed ? 674. How does excessiva
indulgeacd afifect the senses?

16*

368 HITCHCOCK'S ANATOMY

temperature is always agreeable, but painful if much in-
creased. Many odors snuffed in small quantity are pleasant,
but when given to satiety, become disgusting. The probable
design of this provision seems to be to prevent injury by an
inordinate stimulation of any of the nerves. For instances are
on record, where the mucous membrane of the nostrils has
been severely affected by the fumes of ammonia given in
fainting.

675. Habit makes painful Sensations pleasant.— It
is a curious but interesting fact that the pain excited by un-
accustomed sensations may sometimes be exchanged for its
opposite, after the system has become habituated to them.
Thus tobacco and alcoholic liquors are at first disagreeable to
most persons ; but when the disgust has been overcome by
any means a love for them succeeds, and generally a strong
craving for excessive indulgence also.

676. Nerves of Special Sense can perform but one
Function . — The nerves of special sense are incapable of per-
forming any function except that for which they were orig-
inally designed. Thus the optic nerve can perform the func-
tion of vision only, the olfactory only that of smelling, and
the auditory only that of hearing.

677. Effect of Belief on our Sensations. — The effect
of previous belief in modifying our sensations, is shown in
the two cases copied from Carpenter's Physiology. ''A
clergyman told me that some time ago suspicions were enter-
tained in his parish, of a woman who was supposed to have
poisoned her newly born infant. The coffin was exhumed,
and the procurator fiscal, who attended with the medical men
to examine the body, declared that he already perceived the
odor of decomposition, which made him feel faint, and in con-
sequence he withdrew. But on opening the coffin, it was

What instance of this from odors? 675. How does habit sometimes affect painful sen-
sations? What examples? 676. What is said of the function of the nerves of special
sense ? 677. How does our belief affect our sensations ? Give the instance of the infant

AND PHYSIOLOGY. 369

found to be empty ; and it was afterwards ascertained that no
child had been born, and consequently no murder committed.
The second case is yet more remarkable. A butcher was
brought into the shop of Mr. McFarlan, the druggist, from
the market place opposite, laboring under a terrible accident.
The man on trying to hook up a heavy pioce of meat above
his head, slipped, and the sharp hook penetrated his arm, so
that he himself was suspended. On being examined, he was
pale, almost pulseless, and expressed himself as suffering the
acutest agony. The arm could not be moved without causing
excessive pain; and in cutting off the sleev^e, he frequently
cried out : yet when the arm was exposed, it was found to be
quite uninjured, the hook having only traversed the sleeve of
his coat!!"

THE SENSE OE VISION.

DEFINITIONS AND DESCRIPTIONS.

678. The chief organ of this sense is the eye, although its
appendages perform very important secondary functions.

679. Anatomy of the Eye. — The human eye is nearly
globular in form, with a diameter a little less than one inch,
the lateral diameter being one twentieth of an inch less than
the antero-posterior. (Fig. 339, p. 370.) In general struc-
ture it is made up of three membranes, and three humors,
or transparent media, and is covered on the surface exposed
to the air by mucous membrane, which also lines the insido
of the lidj so that the two surfaces at some points are always
in contact.

680. Sclerotica . — The membrane which covers the larg^
portion of the eye is called the Sclerotica, from the Greek

Give the instance of the butcher. 678. What is the chief organ of sight? -679. What
la the shape of the eye ? Its diameter ? Of how many media and membraues ia ik
made up?

370

HITCHCOCK'S ANATOMY
Fig. 339.

Longitudinal Section of the Globe of the Eye. 1, Sclerotic, thiclcer behind than in
front. 2, Cornea, received within Anterior Margin of Sclerotic, and connected with it by
means of a beveled edge, 3, Choroid, connected anteriorly with (4,) Ciliary ligament,
and (5,) Ciliary Processes. 6, Iris. 7. Pupil. 8, Third Layer of Eye, Retina terminating
anteriorly by abrupt border at commencement of Ciliary Processes. 9, Canal of Petit,
encircles the Lens (12) ; the thin layer in front of this canal is the Zonula Ciliaris, a pro-
longation of Vascular Layer of lletina to the Lens. 10, Anterior Chamber of Eye con-
taining Aqueous Humor ; the lining membrane, by which the humor is secreted, is
represented in diagram. 11, Posterior Cliamber. 12, Lens, more convex behind than
before, enclosed in its proper Capsule. 13, Vitreous Humor enclosed in Hyaloid Mem-
brane, and in cells formed in its interior by that membrane. 14, Tubular Sheath of
Hyaloid Membrane, wliich serves for the passage of the Artery of Capsule of the Lens.
15, Neurilemma of Optic Nerve. 16, Arteria Centralis Retinje, embedded in the center.

signifying hard, because it is a firm and stout membrane. Its
color is nearly white, covering the posterior four fifths of the
eye, it is commonly called the white of the eye, and is thickest
in its posterior parts.

681. Cornea. — The external covering of the front fifth
part of the eye is called the Cornea, from the Latin word
meaning horn-like, and in two respects it bears the same rela-
tion to the ball of the eye, as the crystal does to the watch,
since it is fitted into the sclerotic by a beveled edge, as is a
watch-glass, and also because it is perfectly transparent. The
blood-vessels of this membrane are among the smallest in the
body, being too small to allow the passage of the blood-cor-
puscles, and only convey the plasma or serum.

630. Describe the sclerotic coat. 681. What is the cornea? To what may it be oom'
pared in the watch ?

AND PHYSIOLOGY.

371

682. Choroid Coat— Iris. Fig. 34o.

— Ciliary Processes. — The
middle coat of the eye is
made up of three portions,
the Choroid membrane, the
Iris, and the Ciliary pro-
cesses. The first, Choroid, is
named from the fact that it is
entirely made up of blood-
vessels, of a chocolate-brown
color on the outside, and a
deep black on the inside. It
covers the posterior four fifths
of the eye, and corresponds
to the sclerotic coat outside
of it. The Iris, so called from
the diversity of color which

Plan of the Structures in the Fore Part of the Eye, seen in Section. 1, Conjunctiva,
2, Sclerotica. 3, Cornea. 4, Choroid. 5, Annulus Albidus ; before this is is seen the
Canal of Fontana. 6, Ciliary Processes. 7, Iris. 8, Ketina. 9, Hyaloid Membrane. 10,
Canal of Petit (made too large). 11, Membrane of the Aqueous Humor (too thick.) a,
Aqueous Humor ; Anterior Chamber, and (or,) Posterior Chamber. &, Crystalline Lens.
c, Vitreous Humor.

Fig. 341.

- Choroid Coat of the Eye. 1, Carved lines marking the arrangement of Venae Vortl-
cosae. 2, 2, Ciliary Nerves, 8, A long Ciliary Artery and Nerve. 4, Ciliary Ligament
5, Iris. 6, Pupil.

632, Of what three portions is the choroid coat composed ? Give their names. De-
scribe the Iris.

372

HITCHCOCK'S ANATOMY

it presents in different persons — and it is the color of this
which we mean when we speak of the color of the eje — cor-
responds in position to the cornea Ijing immediately under it.

FiG. 342.

Fig. 343.

External View of the Iris. , Anterior Segment of a Transverse Section

of the Globe of the Eye seen from within.
1, Divided edge of the three Tunics ; Sclerotic, Choroid (the dark layer), and
Eetina. 2, Tiipil. 3, Iris, the surface presented to view in this section being
the Uvea. 4, Ciliary Processes. 5, Scalloped Anterior Border of the Eetina.

It is circular in form, containing a few muscular fibers, with
a circular opening through its center, from one third to one
twentieth of an inch in diameter, which is known as the pupil.
The Ciliary processes are minute triangular folds of the Cho-
roid coat, which lie upon the interior surface of the iris, with
their bases directed toward the pupil. Thej are about sixty
in number, and are divided into large and small, the latter
being placed between the former. The Pigmentum Nigrum,
or black paint, is an extremely tenuous membrane, which
lines the inside of the choroid coat. It is of a jet black color,
and is easily destroyed merely by allowing a stream of water
to fall upon it.

683. Retina. — The inner membrane of the eye is. the Re-
tina, which is merely an expansion of the optic nerve, upon

What is the diameter of the iris? . What are the ciliary processes? How many are
there ? What is the pigmentum nigrum ? 683. Describe the retina.

AND PHYSIOLOGY

373

the inner side of a hollow sphere, formed bj the membranes
already mentioned.

684. Microscopic Structure of tliesc Membranes. —
The structure of these membranes, as revealed by the micro-
scope, is very complex. The Cornea ia made up of four sim-
ple membranes, tha Choroid of three, and the Retina of four.

Fig. 344.

--S-1'. .sP^^S^^yW¥M^?€W^^*^!PP^^^^P^

Vertical Section of the Human Eetina and Hyaloid Membrane h, Hyaloid Membrane.
^', Nuclei on its inner surface, c, Layer of Transparent .Cells, connecting the Hyaloid
and Eetina, c', Separate Cell enlarged by imbibition of water, n, Cray Nervous Layer,
■with its Capillaries. 1, Its Fibrous Lamina. 2, Its Vesicular Lamina. V, Shred of Fi-
brous lamina detached. 2', Vesicle and Nucleus detaciied. g, Granular Layer. 3, Light
Lamina frequently seen. g\ Detached Nucleated Particle of the Granular Layer, m, Ja-
cob's Membrane, m'. Appearance of its Particles, when detached. m'\ Its Outer Sur-
face.— Masnified 320 diameters.

The Sclerotic is for the most part made up of white fibrous
tissue, and a large portion of the Choroid coat is composed of
blood-vessels, although the inner membrane — the Pigmentum
Nigrum or black paint — consists of minute six-sided cells re-
sembling a tesselated pavement. The Retina is for the most
part made up of the different forms of nervous tissue and its
membranes.

6S4. Give the microscopic structure of the cornea. Of the choroid, the pigment, and
thti retina.

14:

HITCHCOCK'S ANATOMY

685. Humors of the Eye; Aqueous.— Of tbe three Hu-
mors or liquid substances composing the eye, the Aqueous or
"vyatery is situated in the anterior portion of this organ behind
the cornea, and in front of the crystalline humor soon to be
described. It is a liquid like water, with an alkaline taste,
and only a few drops in quantity. The Iris is placed directly
in the middle of this fluid.

686. The Lens. — The Crystalline Lens or Humor (so
called because it refracts light and is transparent like a crys-
tal) is a double convex lens, the posterior convexity being

Fig. 345.

Fig. 346.

Front View of the Crystalline Lens.

Side View of the Lens. 1, Anterior Fac«.
2, Posterior Face. 3, Circumference.

greater than the anterior, and is located directly behind the
pupil, so that all the light which enters the eye, must pass
through this and be refracted. This lens is made up of con-
centric layers like an onion, and also of three triangular seg-
ments, with their sharp edges directed towards the center,
both of which structures, by boiling the lens in water for a
short time, can be readily seen. Fig. 347 represents the

difference in diameters
of the lens at different
periods of life, a, rep-
resents it at birth, b, at
six years of age, c, its
appearance in an adult,
and c?, after it has been

Fig. 341.

o 0 ()

Crystalline Lens, a. At birth. 6, At six years
old. c. Adult d. Altered by alcohol.

635. How many humors are there in the eye? Describe the aqueous. 6S6. What is
the crystalline humor? What kind of a lens is it? Of how many segments is it made up?

AND PHYSIOLOGY. 375

hardened and partially divided into segments by an immersion
in alcohol.

687. litre oils. — The Vitreous Humor (from its resem-
blance to glass) is of the form of a sphere, with the anterior
portion removed, and constitutes seven eighths of the globe of
the eye. It is a transparent fluid enclosed in a transparent
membrane, and through its central portion from the entrance
of the optic nerve, there passes a small artery to the lens,
"which supplies it with blood.

688. Lachrymal Gland.— Nasal Duct. — At the outer angle
of each eye is found a gland called the Lachrymal gland, nearly
three fourths of an inch in length, and of a flattened oval

Fig. 348.

Posterior View of the Eyelids and Lachrymal Gland. 1, 1, Orbicularis Palbebrarum
Muscle. 2, Borders of the Lids. 3, Lachrymal Gland. 4, Its Ducts opening in the Up-
per Lid. 5, Conjunctiva covering the Lids. 6, Puncta Lachrymalia. 7, Lachrymal Ca-
runcle as seen from behind.

shape. (Fig. 348.) Passing from this gland to the eye, are from
eight to twelve small ducts, which open upon the under side
of the lid near its edge, about one twentieth of an inch apart,
which carry the tears to the eye. By continual winking this

687. From what does the vitreous humor get its name? Describe it. 6S8. Where ara
the lachrymal glands situated? What is their size ? How many ducts have they ? What
do they secrete ? Of what use is winking?

376

HITCHCOCK'S ANATOMY

■^^^' ^^^' fluid is uniformly distributed

over the whole ball of the
eye, and the excess is carried
away from the eye by the
two lachrymal canals, which
commence at the two little
projections near the inner
angle of each lid of the eye,
appearing like minute black
specks. Both of these very soon
unite into a larger tube called
the nasal duct, (Fig. 849,)
which descends inwardly and
empties itself upon the nostrils.
689. Eyebrows. — The
Eyebrows are projecting
arches of fat and skin, cov-
ered with short and thick
hairs which encircle the
upper portion of the
eye. They are provided
with muscles, so that
they can be made to
shade the eye more or
less perfectly, as ne-
cessity may require.

690. Eyelids.— The
Eyelids are movable
membranous and mus-
cular coverings which
are placed directly up-
on the eyeball, and are
designed for protective organs against mechanical violence and
too powerful light. Their free edges are called Tarsal Carti-

Where are the hichrymrtl canals and what do they carry? What is the nasal duct?
6S9. Describe the eyebrows. 690. What are the eyelids ? What are their edges made up
of? What glands directly ia them ?

Lachrymal Canals. 1, Puncta Lachry-
malia. 2, Cul-de-Sac at the Orbital End
of the Canal. 8, Course of each Caual to
the Saccus Lacrymalis. 4, 5, Saccus La-
crymalis. 6, Lower Part of the Ductus
ad Nasum.

Fig. 350.

9 2

Front View of the Left Eye— moderately opened.
1, Supercilia. 2, Cilia of each Eyelid. 3, Inferior
Palpebra. 4, Internal Canthus. 5, External Can-
thus. 6, Caruncula lacrymalis. 7, Plica Semilu-
naris. 8, Eyeball. 9, Pupil.

AND PHYSIOLOGY.

3V7

lages, directly in the substance of which is placed a large
quantity of minute glands, called Meibomian Glands.

Fig. 351. Fig. 352.

1 ^'

Meibomian Gland highly
magnified.

Meibomian Glands seen from the Inner or Ocu-
lar Surface of the Eyelids, with the Lachrymal
Gland— of the Eight Side, a, Palpebral Conjunc-
tiva. 1, Lachrymal Gland. 2, Openings of Lachry-
mal Ducts. 3, Lachrymal Puncta. 6, Meibomian
Glands.

691. Muscles of llie Eye.— The
Ball of the eye is moved by six distinct
muscles, four straight and two oblique
muscles, as is shown in the cut. Their
names are Rectus Superior and Inferior, External and Inter
nal, and Superior and Inferior Oblique.

Muscles of the Eyeball. 1, A small FiG. 353.

Fragment of the Sphenoid Bone
around entrance of Optic Nerve into
Orbit. 2, Optic Nerve. 3, Globe of
Eye. 4, Levator Palpebrae Muscle.
5, Superior Oblique Muscle. 6, Its
Cartilaginous Pulley. 7, Its reflected
Tendon. 8, Inferior Oblique Muscle;
the small square knob at its com-
mencement is a piece of its bony
origin broken off. 9, Superior Eec-
tus. 10, Internal Rectus almost con-
cealed by Optic Nerve. 11, Part of External Rectus, showing its two heads of origin.
12, Extremity of External Eectus, at its Insertion; the intermediate portion of muscle
having been removed. 13, Inferior Eectus. 14, Tunica Albuginea formed by expansion
of tendons of four recti.

691, How many muscles for moving the eyeball ? Give their names.

378 HITCHCOCK'S ANATOMY

FUNCTIONS OF THE EYE.

692. The primary and obvious use of the eye is to receive
the form and color of different objects, and to transmit them
to the brain.

693. Use of llie Coats — Sclerotica — Cornea— Choroid —
Black Paint — Iris — Ciliary Processes — The Retina.— The
use of the firm and hard sclerotic coat is to give a firm attach-
ment to the muscles which move the eye, and also secure pro-
tection to the delicate parts within. The cornea is tough but
transparent, so that the anterior portion of the eye may be
firm and at the same time admit the rays of light. The cho-
roid coat furnishes the blood to the eye, it being for the most
part entirely made up of blood-vessels. It also secretes the
black paint (Fig. 288), which is of great service in absorb-
ing the superfluous or wandering rays of light which otherwise
would obscure the image on the retina. A similar provision
is made by painting black the tube of the telescope and mi-
croscope. The iris regulates the amount of light entering the
ball, by its contraction and expansion. This function is per-
formed by the radiated and circular muscular fibers, the
latter of which contract by the stimulus of strong light;
but if the light be feeble, the radiated contract, and thus
enlarge the pupil. The retina, with the vitreous humor
in front and the black paint directly behind it, receives
the image of the object before the eye. It bears the same
relation to the other parts of the eye as the silvered or glass
plate does in the camera of the photographist. This impres-
sion is carried to the brain by means of the optic nerve.

694. Use of the Humors— Aqueous— The Lens— Vitreous^
— Of the three humors or media of the eye, the aqueous is
the least important, since if by accident or operation it is re-

692, State the use of the eye. 693. Give the use of the sclerotic coat. Of the cornea.
What does the choroid furnish to the eye? Of what service is the black paint? What
does the iris do? What is the function of the ciliary processes? What is the use of tha
retina ? 694. Which is the least Important of tho humors ?

AND PHYSIOLOGY. 3*79

moved, nature will soon replace it ; but this is true of no
other medium. The aqueous humor, however, is of great use
to keep the front parts of the eye in a soft and elastic condi-
tion, and also to furnish a medium in which the iris may
readily be contracted and relaxed. It also aids in properly
refracting the rays of light, so that the most perfect image
may be formed on the retina. The use of the crystalline lens
is also to refract the rays of light, so that an image of suffi-
ciently small size may be formed on the retina. Otherwise,
when we look at any object larger than the diameter of the
pupil, we should be unable to see it, only by successively
looking at minute portions of it. The vitreous humor assists
in the same refraction of the rays, and incidentally subserves
the purpose of fixing at a proper distance the lens, so that the
image may be formed exactly at that point on the retina called
the focus, where it will be the most distinct.

695. iNeed of Three Media.— But what is the necessity for
three media of refraction, and why will not the crystalline lens
answer the whole purpose ? This is owing to some of the
properties of light. Light is composed of seven rays or colors,
some of which are more easily refracted than others ; that is,
some rays are bent farther from a perpendicular to the sur-
face than others. Hence, upon the edges of an image formed
by a single lens, every part of which is of the same density,
we should see several of the prismatic colors, which would give
an indistinct image. In the telescope and microscope this
difficulty is remedied by forming a lens of crown and flint
glass, one of which has a stronger dispersive or refractive
power than the other. In the eye the same error is obviated
by means of the crystalline lens, which has a greater refrac-
tive power than the vitreous humor, and consequently, when
the ray is too much refracted by the crystalline lens, a ccm-

State the \ise of the aqneous. The iise of the lens. What floes the vitreous humor aid
in ? 695. Wliat is the need of three humors ? How many distinct colors does light con-
sist of ? What similar purpose do lenses of different densities answer in telescopes?
Which of the three humors has the greatest refractive power?

88iD HITCHCOCK'S ANATOMY

pensation is effected by the vitreous humor, -which refracts less
than the lens.

696. The Secretion of the lachrymal Glands.— The lach-
rymal gland is designed to secrete a saltish fluid known as the
Tears. This is of great service in lubricating and keeping
moist the surface of the eyeball, so that it may move readily
in its socket, and also to keep the cornea from becoming hard
and dim. The tears also moisten the back part of the nostrils,
and are ultimately poured into the pharynx. The amount of
tears which is daily secreted is estimated at four ounces,
and it is greatly increased by strong emotions, whether pleas-
ant or sorrowful, as it is well known that a person is apt to
cry when very sad or very happy.

697. Service of the Eyelids— Necessity of Constantly
Winliing— Eyelashes.— The eyelids are of service to keep
the light from the eyes when it is too intense, or when it is
necessary to exclude it entirely, as during sleep. Another
valuable service which they perform is to spread the tears
constantly and uniformly over the eyeball. This is the rea-
son why we are constantly but unconsciously winking during
every few seconds of our waking hours. The eyelashes which
line the edges of the lids, prevent the perspiration which is
secreted on the lids from entering the eye, and thus irritating
it, since by the law of capillary attraction the tears will run
towards the free extremity of the hair, where they will accu-
mulate to such a size that they drop off. The eyelashes also
prevent, in some degree, dust from entering the eye.

698. Use of the Eyehrows.— The eyebrows perform a
similar office to the eyelids, though not so important. The
hairs which cover them, like the lashes, convey away the per-
spiration from the forehead, and allow it to fall in front of the
eye, and not directly upon the ball ; while, by means of the

696. What is the secretion of the lachrymal gland? What is the iise of the tears?
What quantity of tears are secreted daily? 697. Of what service are the eyelids? Why
do we constantly wink? Of what service are the eyelashes? 698. What service do tbfc
eyebrows perform ?

AND PHYSIOLOGY. 381

muscles attached to the integuments, whenever it is desired
the J bring the brows in front of and above the eje in such a
manner as to afford it a very considerable protection from ex-
cessive light.

699. Short and Long-Sightedness.— The phenomena of
short and long-sightedness are worthy of a passing notice.
Short-sightedness results where the lens of the eye has too
much convexity, which causes the image to be formed in front
of the retina. In such persons the eye generally has greater
prominence than in others. But persons thus affected will
probably in later years have better eye-sight than if short-
sightedness had not existed. A too much flattened state of
the lens occurs in those who are long-sighted. This is gener-
ally the case with those somewhat advanced in life. In this
case the distinct image will be formed behind the retina, and
it requires a convex lens, in the form of spectacles, to correct
the error.

700. Other Interesting Phenomena of Vision.— A few
other phenomena connected with the function of vision de-
serve attention. One is the fact, that although we have two
eyes and two distinct images are transmitted to the brain,
yet but one object is seen. And if we look at an object with
only one eye, we see the image nearly as distinct as with both
eyes. Another is, that although the image on the retina is
inverted, yet to the mind it appears in its true position. For,
since the rays of light pass through the lens in nearly straight
lines, the ray coming, for instance, from the top of a tree, will
fall upon the lowest part of the retina, while the ray coming
from the bottom will strike the upper part, and hence the
image will be inverted, although to the " mind's eye" it will
be erect. Another fact is equally wonderful. We are able
to see with distinctness an object only a few inches from our

699. What is the cause of short-sightedness? What is the reason of long-sightedness?
What kind of a lens is required for long-sighted people, and why ? 700. What curious
facts connected with the physiology of vision ?

382 HITCHCOCK'S A X A T O M T

ejes, and almost instantly, by turning them to a mountain
top several miles distant, we can see an object there with per-
fect cleaarness. No optical instrument can be made which
will so quickly do this, for it is necessary to make a new ad-
justment of the lenses to adapt it to different distances, but
the eye is at once ready. It is supposed that this adjustment
is effected by a shortening or lengthening of the diameter of
the crystalline lens, or by drawing the lens towards the pos-
terior part of the eye, by means of a few muscular fibers
called the ciliary muscle, running from the bones of the nose
to the cornea, which by their contraction would force the
aqueous humor upon the crystalline lens in such a manner as
to flatten it, and by a relaxation of the same fibers a dilata-
tion in an antero-posterior direction is effected, and that in-
stantly.

701. Experiment for Seeing the Arteries of one's own
Eye. — The image of the arteries of one's own eye can be
readily seen in the following manner. In a dark room place
the left hand over the left eye, and in the right hand hold a
lighted candle by the right side of the head, and very near
to it. Then with the right eye open, looking towards the
darkened wall, move the candle up and down rather quickly,
and in a few seconds dark branches will appear at a short dis-
tance from the eye, looking like the limbs of a tree, which are
images of the arteries distributed on the retina.

702. limits of Vision . — ^What is the size of minute ob-
jects that can be seen by the naked eye ? Ehrenberg, an
eminent microscopist, says that nearly all eyes have equal
power to discern minute objects, whether long or short-sighted.
The smallest square magnitude visible to the naked eye,
either of white particles on a dark ground, or the reverse, is
about the ^—th of an inch. Brilliant particles which pow-

IIow is tho telescopic and the microscopic power of the eye explained ? 701. How can
we see tho image of the arteries of our own eyes? 702. What is the smallest square sur-
face that can be seen with the naked eye ?

AND PHYSIOLOGY. 383

erfully reflect light may be distinctly seen when not half the
size of the foregoing. Thus gold dust the ttV ith part of an
inch in diameter is visible in common daylight. Lines may
be more readily seen than points. Opaque threads 4 77V irth of
an inch in diameter can be seen when held towards the light.
Attention also greatly helps to discern minute objects, or at
least to retain them in sight when once pointed out. Thus
we are often able to see a faint star in the sky or a sliip in the
horizon after they have been pointed out to us, although they
were not seen before. "I myself," says Ehrenberg, "can
not see oTVo^th of an inch, black or white, at twelve inches
distance ; but having found it at from four to five inches
distance, I can remove it to twelve inches and still see the
object plainly."

703. Color Blindness. -Many people are afflicted with an
inability to distinguish certain colors of the solar spectrum.
This is called Color Blindness, or Daltonism.

704. Formerly it was supposed that this affection was very
rare, but later researches show it to be quite common. Ac-
cording to experiments made by Dr. Wilson upon 1154 per-
sons in Edinburgh in 1852 and 1853, it was found that^ — ^

1 ia 5 5 confcuuds iv.l W't'.i brown. q

1 in CO confounds brown with green. • p

1 ia 43 con!buuds bhi3 v,"iLli green. O

Hence one in every 17.9 persons is color blind.

THE SENSE OF VISION IN ANIMALS.

705. Tapetum— Pupil— Nictitating Membrane— Harde-

rian Gland. — The general anatomy of the eye of mammals c

differs but slightly from that of man. Between the sclerotic x

and choroid in some animals is found another membrane of a f

. Ho-w is it -n-ith brilliant particles? ITow is the ready vision of lines compared with
points? How small a thread can be seen by the naked eye? What effect has the fa-
miliarity with an object ? 703. What is color blindness ? How often is this peculiarity
found f What coiora are most commonly confounded ?

17 ■ '

584 HITCHCOCK'S anatomy"*

metallic brilliancy, with different shade of color, known as
the Tapetum. In horses and cows it has a variegated luster
of green and blue, while in the tiger, cat, and whale it is of
a silvery brightness. The shape of the pupil in the wolf
and dog, which need vision in all directions, is circular ; while
the fox and cat, which need a vertical range more than any
other, have a perpendicular slit only. In cattle and the more
timid grazing animals which obtain their food from the ground,
and need to look behind with ease when pursued, the pupil is
a horizontal ellipse. Nearly all mammals except man and
the apes, have a third lid, which is a transparent membrane
that is frequently slid over the ball by a peculiar muscular
apparatus. This is called the " haw" or Nictitating Mem-
brane, and, especially in birds, serves the purpose of remov-
ing impurities from the eye, and also of spreading the secre-
tions over it, in order to keep it moist and transparent. In
addition to the lachrymal gland, in all animals which have
the third lid there is another gland called the Harderian Gland,
which prepares another secretion similar to and for nearly the
same purpose as the lachrymal.

706. Kycs of Birds — Pecteii M a r s u p i u m .— All birds,
without exception, are provided with perfect and well devel-
oped eyes. They are always large, and largest in birds of
prey. They are but slightly movable themselves, but this
want of motion is compensated by the great mobility of the
head. The sclerotic coat is strengthened in front by a series
of bony plates, fourteen or fifteen in number, interposed be-
tween its fibrous layers, a great use of which is to give at-
tachment to the special muscular apparatus for adapting the
eye to see objects at different distances. The anterior chamber
is proportionally larger than in any other animals, so that the
iris is far back from the cornea. The iris has different shades
of color, commonly yellow or brownish. The yellow color of

70^. What is the tupetum ? What is its color? What is the shape of the pupil In tha
wolf, dog, and in cattlo? What is the Nictitating: mernbrant'? Of what service is the
" haw ?■' For what purpose is the Harderian (jland ? 7 '8. What Is said of the perfection
of eyes In birds? How hi the sclepotie coat strongthenexl In them?

AND PHYSIOLOGY. 385

this part in the owl is owing to the presence of cells contain^
ing fat. A curious structure is found in the eye of birds that
is found in no other animal. It is called the " Pecten Mar-
supium," and consists of a layer of blood-vessels arranged in
several plications varying greatly in size. It extends some-
times as far forwards as the lens, and is covered by black pig-
ment. Its probable use is that of absorbing rays that enter
the eye obliquely, and thus rendering sight from a forward
direction more definite and sharp. The membrana nictitans
jind the Harderian glands are present in these animals in their
fullest perfection.

707. Eyes of Reptiles.— All reptiles have two eyes. In
most, especially in serpents, they are small in comparison
with the size of the body ; in the frog, however, in the gechos
and chameleons they are large. In some they are covered by
the skin. In the serpents there are no eyelids, but the skin
which covers them is kept moist by a lachrymal gland, and
thus performs the service of a lid. In other reptiles there
are three lids, the middle one of which moves at right angles
to the other two. The lachrymal gland often is very large.
In some turtles and lizards there is a ring of bony plates
which supports the eyeball. The lens has difierent degrees
of sphericity in different animals.

708. Eye of Fishes— Pigmentary Spots.— The eyes of
fishes are remarkable for the great size and spherical form of
the lens, which is necessary in order to give sufficient refrac-
tion to the rays of light that come from the dense medium in
which they live. The size of the lens varies greatly, being
largest in the bony fishes and smallest in those which lie
buried in the mud like the eel. The lowest stage, however,
is seen in the amphioxus, a condition which greatly resembles

What makes the yellow color of the iris In birds? What is the pecten marsupium?.
What is its use? 707. What is said of the eyes of reptiles? What of the bony platea
Id the eyeball? 70S. V/hat characterizes the eyes of fishes? What oa«s hava the
largest?

386

HITCHCOCK'S ANATOirT

Fia. 354.

that of the lowest invertebrata, being nothing but two pig-
mentary spots. The eye is but slightly movable in fishes,
since the body, and consequently the head, can be so readily
moved in any direction through the water.

709. Compound Eyes
— Number of F acets.—
The eyes of many of the
articulate animals are con-
structed upon the com-
pound type, that is, the
visual organs are made up
of an aggregation of single
eyes placed upon each side
of the head, each one of
which is a complete visual
instrument, but can re-
ceive and bring to a focus
only those rays of light
which come to it from a particular direction. In many in-
sects each composite eye forms a hemispherical protuber-
ance upon the side of the head, which, when examined by the

Fig. 355.

Head and Compound Eyes of the Bee, sbov-
J*^g the Ocelli in situ on one side (A), and dis-
placed on the otliei- (B). a, a, a, Stemmata. h,
&, Antennae.

A, Section of the Eye of Melolontha Vulgaris (CockchafFer). B, A portion more highly
Magnified, a. Facets of the Cornea, b, Transparent Pyramids surrounded with Pig-
ment, c, Fibers of the Optic Nerve, d, Trunlc of the Optic Nerve.

What are the pigmentary spots? 709. What are compoun<l eyes? What sub-kingdotn
do they characterize? How does the eye appear on many Insects ?

AND PHYSIOLOGY. 387

, magnifying glass, is found to be made up of a vast number
. of facets, which are generally hexagonal. In the common
house fly there are 4,000 in each eye, in the dragon fly
24,000, and in one species of the beetle 25,000. Each one
of these facets is found to be the end of a little eye, the frus-
trum of a slender pyramid standing by its apex on a bulbous
expansion of the optic nerve. The interior of this pyramid
is filled with a trans- Fig. 356.

parent substance which
represents the vitreous
humor, while between
the frustra is found the
black pigment. Both

surfaces OI these laCetS -^^^ ^f FossH TnboUte constructed on the same

are found to be convex, p^^"-

and it has been calculated that the focus of these lenses would
be at a point just at the extremity of the pyramid where it
joins the optic nerve. And since the rays of light entering
one of these facets can not enter the other on account of the
black pigment intervening between them, the i-ange of vision
to the insect would necessarily be very limited were it not for
their enormous multiplication, by which in reality a separate
eye is provided for every point to be viewed, thus giving to
the insect as perfect an apparatus of vision as we have, al-
though immovably fixed on the body.

710. S t e m m a t a . — Besides the composite eyes, insects usu-
ally have a small number of simple eyes situated upon the top
of the head, called Stemmata. If they are covered with paint,
the movements of the insect are constantly upward.

711. Other Articulates. — A few insects that live in dark
places have no eyes. Some Crustaceans have compound eyes
without facets, and others with them. Some Annelids have
eyes, others none. The Rotatoria have vision, but the Hel-

What number of facets are there in the house fly and in the dragon fly? Give the an-
atomy of each facet or pyramid. TIO. What other organs of vision besides compound
eyes do insects have ? If the stemmata are removed what is the result ? Til. What
of the eyes of articulates ?

388 HITCHCOCK'S ANATOMY

minths are witliout ejes. Among Arachnida (spiders) the
ejes bear a near relation to the vertebrate type of eyes. Their
number is much less than among the other articulata, seldom
more than eight, and are to be compared more with stemmata
than with compound eyes. Sometimes these are collected
into one mass upon the second segment of the body, and some-
times they are arranged symmetrically upon the median line.

712. Eyes of Molluscs.— The organs of vision in the
Acephala are numerous, rising as high as forty in the genus
Pinna, where they are placed in the mantle. The Cephalo-
phora have generally two eyes. In the Cephalopoda the eyes
are disproportionately large, and possess nearly all the parts
found in the eyes of vertebrates.

713. Eyes of Radiates. — The Polypi show a sensibility
to light, but no eyes have been discovered in them. The
Acalephae seem to have the sense of vision, and Agassiz seems
to have ascertained the presence of an organ for this purpose
in some of them. It is more doubtful in respect to the Echi-
noderms.

What eyes have spiders? 712. What are the eyes of molluscs? 713. What is gaid •{
the organs of vision among radiates ?

AND PHYSIOLOGY.

389

THE SENSE OF HEARING.

DEFINITIONS AND DESCRIPTIONS.

714. Parts of the Ear. — The organ of hearing is made
up of three distinct portions : the Pinna or external ear, the
Tympanum or middle ear, and the Labyrinth or internal ear.

715. The Pinnn. — The Pinna, commonly known as the
Ear, is a cartilaginous plate with numerous irregularities upon
its surface, and having upon it a few muscular fibers, which

Fig. 357.

Fig. 358.

A View of the Left Ear in its Natural
State. 1, 2, The origin and termination
of the Helix. 3, The Anti-Helix. 4, The
Anti-Tragus. 5, The Tragus. 6, The Lo-
bus of the External Ear. 7, Points to the
Scapha, and is on the front and top of the
rinna. 8, The Concha. 9, The Meatus
Auditorius Ex tern us.

An Anterior View of the External Ear,
as well as of the Meatus Auditorius, Laby-
rinth, etc. 1, The Opening into the E:ir
at the bottona of the Concha. 2, The Mea-
tus Auditorius Extcrnus or Cartilagin-
ous Canal. 8, The Membrana Tyrnpani
stretched upon its Eing. 4, The Malleus.
5, The Stupes. G, The Labyrinth.

714. What are the three parts of the organ of hearing ? 715. Describe the pinna.

390

HITCHCOCK'S ANATOMY

are in fact rudimentary muscles, 5 in number. In some men
thej have been so fully developed that the ears could be
moved by their action, while among quadrupeds there are but
few that do not possess this power. The Pinna somewhat
resembles a funnel, forming at its base an irregular tube called
the Auditory Canal, about half an inch in diameter and an
inch in length, which terminates with the Tympanum. A
f3W stiff hairs are found upon the sides of this canal, and in
the lining membrane some glands, which secrete the wax of
the ear.

Fig. 359.

716. The Tympanum.— Membrana Tympani.— Little
Bones of the Ear. — The Tympanum is an irregular cav-
ity located in the petrous portion of the Temporal bone,
measuring rather more than one half inch in its longest
diameter. At the point where the Auditory Canal joins

the Tympanum, the
Membrana Tympani is
found, which is simply
an impervious mem-
brane stretched between
the two cavities, dip-
ping inwards at an an-
gle of forty-five degrees.
To this membrane are
attached three muscles
for the purpose of ren-
dering this membrane
lax or tense, as may be

Yiew of the Cavity of the Tympanum, the Ossicula Auditus, and their Muscles, magni-
fied, a, a, Cavity of the Tympanum, b, Membrana Tympani, or rather the osseous
circle to which it is attached, c, Handle of the Malleus, resting on the middle of tho
Membrana Tympani. d, Head of the Malleus articulating with the Incus, e, Long
Handle of the Malleus, passing into the Glenoidal Fissure ; the Anterior Muscle of tho
Malleus is attached to it. f, Internal Muscle of the Malleus, g, Anvil. Ji, Lenticular
Bon(5. i, Stapes, k. Muscular Stapedius.

Can the ear ever be moved? How many rudimentary. muscles are placed on it? T16.
What is the tympanum ? Describe the membrana tympani.

AND PHYSIOLOGY. 391

Fig. 360. Fig. 361.

a &
▲ 3

f

d

Membrana Tympani from the Outer (A), and from Small Bones of the Ear. a, The

tlic Inner (B) Sides. 1, Membrana Tympani. 2, Mai- Malleus. &, The Incus, c, The
leus. 3, Stapes. 4, Incus. Lenticular Bone, d, The Stapes.

required. This cavity contains the "little bones of hearing,"
as the J are sometimes called. These are the Malleus, a ham-
mer,— the Incus, an anvil, — and the Stapes, a stirrup, be-
cause they somewhat resemble these instruments. The Mal-
leus lies directly against the drum of the ear (Membrana
Tympani), its opposite side connecting with the Incus, which"
is in connection with the end of the Stapes, thus forming a
continuous chain of bones through the Tympanic Cavity. In
the walls of the Tympanum are no less than ten opejnings,
the most important of which are, one downwards into the
Pharynx known as the Eustachian Tube, another into the
Labyrinth, which is closed by the foot of the Stapes, and an-
other outwards to the External Ear.

TIT. Labyrinth. — Cochlea.— Semicircular Canals —
Perilymph .—V e s t i b u 1 e . — The Internal Ear is called a Laby-
rinth because of its very complicated structure and func-
tions. (Eig. 362, p. 392.) It mainly consists of a series of
semicircular canals and cavities, of which some are made up
of cartilage, and others of bone. The canals are composed of
bone, three in number, and their respective planes arranged at
right angles to each other. They contain the nerves of hear-
ing and other substances, which facilitate the transmission of
sound. Gne of these portions is named the Cochlea, because

What are the names of the bones of the ear ? How many openings are there in the
tympanum ? TIT. What is the labyrinth ? Of what is it mainly made up ?

:392

HITCHCOCK'S ANAT6MY

Fig. 3G2.

>. A View of the Labyrinth and Tympanum of the Ear, with the Bones in Situ, highly
magnified. 1, Processus Longus of the Malleus. 2, Its Processus Brevis. 8, Its Manu-
brium. 4, Its Neck. 5, Its Head. 6, Body of the Incus. 7, Its Processus Brevis. 8,8,
Its Processus Longus, with the little head for articulating with the Stapes. 9, The Head
of the Stapes. 10, Its Anterior Crus. 11, Its Posterior Crus. 12, Its Base. 13, 14, 15,
The first turn of the Cochlea. 16, 17, 18, Its second turn. 19, Its half turn. 20, The
Cupola. 21, The Fenestra Kotunda. 22, 23, The Vestibule. 24, 25, 26, Anterior Semi-
circular Canal. 27, Its junction with the Posterior Canal. 28, 29, 80, 31, The Posterior
Semicircular Canal. 82, 83, 34, 35, The External Semicircular Canal. The Enlargements
on these Canals are called Ampullaj.

it resembles a snail shell, and some of the others semicircular
canals, because they are tubes containing fluid called Peri-

FiG. 363.

Cochl«a without the Nerv^.

AND P HTSI OLOGT.

393

lymph and nerve fiber, which take the general direction of a
semicircle. Of these cavities, however, tiie cochlea is not
filled with the perilymph, but contains the finest subdivisions
bf the auditory nerve. Besides the cochlea and semicircular
canals there is a small three-cornered cavity called the Vesti-
bule, into which the five openings of the semicircular canals
enter.

718. Auditory Nerve.— The nerve of hearing belongs to
the eighth pair of Cranial nerves. It divides into tv>o
branches just before it enters the ear, one of which is called
the cochlear branch, because it is sent to the cochlea, and an-

FiG. 364.

Auditory Nerve taken oi:t of the Cochlea. 1, 1, 1, Trunk of the Nerve. 2, 2, Its fila-
ments in the Zona Ossea of the Lamina Spiralis. 3, 3, Its Anastomoses in the Zona Vcsj-
cularis.

other the vestibular, since it enters the vestibule, a portion of
the labyrinth. Besides this a branch of the facial nerve en-
ters the ear in company with the auditory..

719. Location of the Internal Ear.— In man and all
the higher animals there, are two separate organs of hearing,

Describe the cochlea. -What are the semicircular canals ? What are they filled with?
ns. What Is tlio nerve of hearing? 719. In what 'bono is the ear located ? . - .

894 HITCHCOCK'S ANATOMY

or an ear upon each side of the body, and no internal connec^
tion exists between them, so that one may be injured or de-
stroyed while the other performs its office. In fact, the inter-
nal ear is protected by the hardest bone (the temporal) in the
body, and is inclosed in a bony sac to which the only opening
of any considerable size is that of the auditory canal.

FUNCTIONS OF THE EAR.

720. Functions of the Pinna.— The object of the pinna is
to convey sound to the auditory canal. This it does by con-
duction and convection ; that is, it acts as a funnel to collect
the vibrations of air a,nd transmit them to the auditory canal,
and also conducts sounds by means of its own substance in
the same manner as a stick of timber conveys the sound made
by the scratching of a pin to its opposite extremity with great
distinctness. Hence the use of the external ear is to collect
sounds from as large a surface as possible, and concentrate
them at the small end of a funnel, so as to increase somewhat
their intensity. The probable design of the ridges and fur-
rows upon the pinna is to give a greater exposed surface to it
as well as to receive vibrations more accurately which come
in various directions.

721. Use of the Auditory Canal. — The use of the audi-
tory canal is to give greater intensity to the sounds collected
by the external ear. This can be illustrated by placing a
long tube close to the ear, while another person speaks at the
other extremity. The voice will be greatly increased in in-
tensity, because every vibration is transmitted to the ear, and
none are dissipated upon the air or surrounding substances.
The auditory canal performs the same office, although in a less
degree than in the above experiment. This canal also exists

Is there any cominunication between the two ears? 720. What is tLe object of tlio
pinna? How does it convey sound to tho internal ear? Why is the pirtia of .«uch an
tineven surface ? 721. Of what service is the auditory canal ^ ■ How may lt4» use b« iUus*
trated? ' ■ ._ ' .

AND PHYSIOLOGY. 895

for protection to the membrana tympani and the delicate or-
gans of the ear, which must be placed within the head to
such a distance that no harm could come to them from exter-
nal violence.

T22. Fnnction of Membrana Tympani— Use of the ''Lit-
tle Bones." — The membrana tympani is a very thin and elas-
tic membrane, not half an inch in diameter, which is designed
to receive all the vibrations of the air falling upon it. On
this account it is stretched directly across the auditory canal,
and is so arranged that by means of muscles it may be ren-
dered more or less tense, so that if it is desired to catch a
very faint sound, the drum may be made so sensitive as to
catch the slightest vibration. The sound received by the
drum of the ear is transmitted to the auditory nerve by means
of the chain of bones already mentioned, the broad side of the
malleus resting directly against the drum, and the broad end
of the stapes closing the opening in the semicircular canals
w^hich contain the nerve of hearing. The use of this arrange-
ment seems to be to catch all the vibrations of the drum, and
instead of allowing them to expend themselves upon the air
in the tympanum, to transmit them directly to the auditory
nerve. The use of the cavity of the tympanum seems to be
to allow a free vibration of the membrane of the drum. An-
other reason for the large size of the tympanum is to prevent
the conveyance of sound to any other part of the ear but the
semicircular canals, and that by means of the chain of little
bones. And in order to convey the sound only to the nerve
of hearing the stapes joins on to the canal, not by a solid ar-
ticulation, but simply by cartilage, so that none of the vibra-
tions can be conveyed to the walls of the canals, but all to
the nerve.

723. Fnnction of Enstachian Tube.— The design of the

What does this canal protect? 722. What is the function of the membrana tympani ?
Of wi^at use are .the " little bones ?" What service, is rendoreU. by the tympanum ?. How
does the stapes unite with the canal ?

396 HITCHCOCK'S ANATOMY

Eustachian tube is evidently to allow of equal atmospheric
pressure upon both sides of the membrana tympani. For
were theair in the tympanum closely confined, the atmosphere,
varying as it does in density, would sometimes create such a
pressure on the drum that all vibrations would be indistinctly
conveyed to the brain. This is the same arrangement that is
found in bass and tenor drums used for musical instruments,
a small orifice always being necessary to give free access to
the air. Hence, when we have a cold, or especially a sore
throat, where the mucous membrane is inflamed, we often find
hearing difficult, because the lining membrane of the Eus-
tachian tube is so much swollen that air can not pass through.
Also when the same condition prevails we can, by swallowing
the small amount of saliva in the mouth with considerable
force, drive so much air into the tympanum that a sense of
fullness occurs in the ear, which continues until the air has
found some means of escape.

724. Functions of the Internal Ear.— The uses of all the
parts belonging to the internal ear are not perfectly under-
stood. Probably, however, the labyrinth and cochlea serve
to give as great expansion as possible to the nerve in the
small space provided for it. And the use of the fluid filling
the labyrinth is to secure all the vibrations coming in through
the bones of hearing, and give them greater intensity. Some
experiments worked out by Muller, a German physiologist,
throw considerable light on the subject. He found that
sounds passing directly into water from the air lose consider-
able of their intensity ; but if a tense membrane is placed be-
tween the two, greater intensity is produced. The intensity
is also greatly increased when to this membrane is attached
a small solid body which communicates with the water alone.
This seems to show why the drum receives all the sound

723. What is the use of the Eustachian tube ? In what instrutnenfaj of music is there
h similar arrangement? Why docs partial deafness sometimes accompany a cold ? 724.
What is said of the functions of the internal ear? Eelate the experiments made by
Muller.

AND PHYSIOLOGY. 397

ratner than some other part of the ear, and also the value of
the three small bones of the ear, at one extremity fastened to
the drum and at the other by cartilages to the semicircular
canals. Other experiments also showed that a solid body of
the form of the stapes alone was the best to communicate with
the auditory nerve.

725. Function of the Cochlea and Semicircular Canals.
—It has been thought by some that the cochlea enables one
to determine the pitch of sound, since animals which possess
the fullest development of this organ have the largest range
of voice. Another speculation is, that the semicircular canals
aid in the determination of the direction from which sounds
come, since in animals where they exist, they are always
placed at right angles to each other.

725 «. Three Physical Properties of Sound.— The three
physical peculiarities of sound are intensity or loudness, pitch
or length of the waves, and quality, or the difference between
the same note on a flute and violin, although equal in intensity
and pitch. And a theory has been proposed, substantiated by
many facts, that the membrana tympani enables us to deter-
mine the intensity, the cochlea the pitch, and the semicircular
canals the quality of sound.

THE SENSE OF HEARING IN ANIMALS.

726. External Ears — Semicircular Canals— Cochlea —
Os Quadrat urn. — All mammals, as a general rule, have ex-
ternal ears. These, in some animals, like the bat, are enor-
mously developed in proportion to the dimensions of the body.
Besides, in several genera they can be turned in any direction
the anifflai may choose. In man the" ear consists of hut' one

725. What suggestion has been made of the use of the cochlea and semicircnlar canals?
725 a. What are the three physical peculiarities of sound ? 726. What mammals have
external ears? What Is said of thetn in the bat? How many pieces has the pinna ia
most animals?

398 HITCHCOCK'S ANATOMT

piece, while in the other mammalia it consists of three. But
the most important part of this organ, the labyrinth, agrees
in its structure throughout the whole class. The greatest
variation that exists is in the semicircular canals and cochlea.
In the cat the canals form the segment of a circle, while in
the goat thej furnish a portion of an ellipse, and in the horse
a parabolic curve. The cochlea varies in the number of its
coils. In the whale and dolphin it makes but one and a half
turns ; in man two and a half; in the ornithorjnchus half a
coil much resembling that of a bird ; while in the squirrel it
makes nearly four turns. No physiological effect of these
variations has as yet been given. In man and the apes the
whole cavity of the tympanum is concealed in a portion of
the temporal bone, but in all other mammals we find a pecu-
liar tympanic bone which varies exceedingly in the different
classes.

727. Ear of Birds. — There are but few birds which have
any thing like an external ear. One species of owl, however,
has a membranous concentric fold which can be used as a
valve. The cochlea has the form of an obtuse cone, which at
its extremity swells into an oval tubercle. The tympanic
cavity communicates with cavities in the cranial bones, which
greatly increases the resonance of sound, in the same manner
as the sounding-board in the piano, or the main body of a
violin or violincello.

728. Hearing in Reptiles.— Although reptiles present a
more imperfect form of the organ of hearing than mammals
or birds yet they possess the tympanum, a membrana tym-
pani, and a chain of ossicles or little bones. Also a cochlea
is found, which is most fully developed in crocodiles and formed
almost as in birds.

How do the canals differ in different animals? What variation in the cochlea? . What
is the OS quadratum ? I2Z. What bird ias external ears? Wliat is said of .the. .cochlea
in birds? What does the tympanum communicate with? What is the use of this ar,
rangement? 728. What is said of the organs of hearing in reptiles ?

AND PHYSIOLOGY. 399

729. Hearing of Fishes.— Among the lowest order of
fishes the organ of hearing is simply a sac, which is full of a
fluid that contains small bones or bits of bones called otoliths,
and the auditory nerve is distributed upon its walls. In
almost all fishes there is a more or less perfect form of the
semi-circular canals. In some fishes the swimming bladder
extends to membranous spaces in the cranium which are in
connection with an auditory apparatus.

730. Articulates. — Among the Crustaceans hearing has
been observed only among the Decapods. The sense exists
in the Arachnoids, but no organ has been found. The same
is true of Insects, Annelids, and Helminths.

731. M 0 1 1 n s c s . — Hearing has been ascertained in Lamelli-
branchiata. In Cephalophora it is of a low grade : but an
auditory nerve and organs exist in the Cephalopoda.

732. Radiates . — The organ of hearing exists in the Polypi
and perhaps the Acalephs, but has not been discovered in
the other Radiates. , .

SENSE OF TOUCH.

DEFINITIONS AND DESCRIPTIONS.

733. Location of the Sense of Touch.— The organ of touchy
with the exception of the upper surface of the tongue, is the
skin. This in some parts is much more sensitive than in

729. Do fishes have the regular organs of hearing ? What organs do they liave in a
rudimentary state ? 730. What apparatus of hearing do articulates possess ? Do they
seem to hear sounds? 731-732. What is said of the sense of sound in molluscs and rad*
ates ? 73-3. Where are the organs of touch located ?

400

HITCHCOCK'S ANATOMY

otherSj since some portions of the skin are more fully crowded
with nerve fibers than others. We are conscious of resistance
if we place a substance in contact with anj part of the bodj ;
and although we are able with the tips of the fingers to tell,
whether a body, which is pressed on them, is circular or rect-
angular, yet we can not with certainty decide the same thing,
if the substance be pressed upon any other part of the body.

734. The Direct Instruments of T o u c li .—The direct in-
struments of sensation are minute loops of nerve fibers from
the posterior roots of the Spinal' Column, lying in the true

Fig. 365.

Nerves of Sensation at the Extremity of fhe Human Thumb.

skin, which are covered only by the Epidermis, as is seen in
Fig. 365. These nerves of sensation are never known to ter-
minate in a free extremity, but always in loops; and in the
hand and foot are associated with the Pacinian Corpuscles,
described under the nervous system.

735. Papillae. —Those
parts of the skin which are
the most sensitive, are cov-
ered with minute projections
called Papillae, which seem-
to be mere elevations beyond
the general surface of the

Pig. 366.

PapillfB of the Palm of the Hand.

What is said of the whole cutaneous surface ? , 734. What are the immediate instru-
ments of touch? How do the sensitive nerves always terminated 735. Describe the
papillfe.

.AND PHYSIOLOGY. 401

skin, in which are found the loop of a nerve, and a blood-
vessel with some cellular tissue. The main use of them seems
to be to place the nerve in such a position, that it will be most
easily impressed with whatever external substances it may be
brought into contact.

FUNCTIONS.

736. The Superficial Parts of the Body most
ahundantly Supplied with Nerves. — The parts of the
body lying deep beneath the skin, are but sparingly supplied
with nerves of sensation, which is a great comfort to those un-
fortunate persons who are subjected to surgical operations,
since the most painful part is in cutting through the skin,
which is the quickest part of the operation. This, however,
is the case only when the deep parts are in health (including
the bones) ; for if any of these parts, and especially the bones
and ligaments, are diseased, they constitute a source of the
greatest pain. The necessity of this arrangement is obvious
from the protection which the surface of the body requires
from violence and heat. Were it not for these body -guards^
we by our other senses should seldom know when friction or
heat was consuming the skin, nor when cold was destroying
its vitality.

737. Value of this Sense to the Bliud.— To those de-
prived of the sense of vision, this sense is of great value, since
it is by this only that they are enabled to pursue any labor,
or instruct and please themselves by raised alphabets, or
play upon musical instruments. And it is interesting, not to
say wonderful, to see what accuracy is acquired by the blind
in detecting true from spurious coins, or in distinguishino^ the
quality of cloth by feeling alone. It is said on good author-

What is the function of the papilla? 736. Why are the superiicial parts of the body
the most abundantly supplied with sensitive nerves ? Why does the skin need sensibil-
ity? 737, What is said of the value of this sense to the blind? What examples ara
mentioned as illustrating its extreme acuteness in the blind ?

402 HITCHCOCK'S ANATOMY

it J, that one blind man became a botanist, another a con-
chologist, and another a land surveyor, simply bj the aid of
touch.

738. Effect of Habit on Location of Sensation. —
Habit has a wonderful power in the location of sensations on
the skin. Thus it is frequently the case, after an amputation of
a limb, that the patient declares that he feels pain in the re-
moved portion. This is owing to some irritation in a fiber or
fibers of the remaining nerve trunk, which were originally
sent to the supposed seat of the pain, and from habit the suf-
ferer locates it in the removed part. Also after the Talia-
cotian operation — which consists in making a new nose from
the skin of the forehead, — if the nose itches, the patient
scratches the forehead as the seat of the irritation.

739. Insensibility produced by a long continued
Action of some painful Stimulus. — It is sometimes the
case that the nerves are rendered insensible by the moderate
but long continued action of some painful stimulus. A com-
plete insensibility of the skin may be produced, so that the
severest surgical operations may be performed without pain,
by the application of snow and salt mixed in equal portions.
Heat will also do the same thing, as shown by the following
example. ''A traveling man one winter's evening laid him-
self down upon the platform of a lime kiln, placing his feet,
probably benumbed by the cold, upon the heap of stones
newly put on to burn through the night. Sleep overcame
him in this situation : the fire gradually rising and increasing,
until it ignited the stones upon which his feet were placed.
Lulled by the warmth the man slept on ; the fire increased
until it burned one foot and part of the leg above the ancle
entirely off, consuming that part so efiectually that a cinder-
like fragment was alone remaining, and still the wretch slept
on, and in this state was found by the kiln man in the morn-

738. What effect has habit upon localizin? our sensations? 739. How may insensibility
be sometimes brought about ? What wonderful example ?

AND PHYSIOLOGY. 403

ing. Insensible to any pain, and ignorant of his misfortune,
he attempted to rise and resume his journey, but missing his
shoe, requested to have it found : and when he was raised,
putting his burnt limb to the ground to support his body, the
extremity of his leg bone — the tibia — crumbled into frag-
ments, having been calcined into lime. Still he expressed no
sense of pain, and probably experienced none, from the grad-
ual operation of the fire, and his own torpidity during the
hours his foot was consuming."

THE SENSE OF TOUCH IN ANIMALS.

740. "It is probable that among the lower animals the
proportion of intuitive perceptions is much greater than in
man ; whilst on the other hand his power of acquiring per-
ceptions is much greater than theirs."

741. Touch in Mammals.— Cat, Rabbit, Elephant,
Bat. — Among Mammals touch ordinarily depends on little
projections known as papillae, which contain a loop of a sensi-
tive nerve. In man this structure is principally found in the
tips of the fingers, but in the Monkey it is found in both the
hands and feet. In a majority of mammals the surface of
the nose, upper lip, and the vibrissas or whiskers, as seen
on the face of the cat, are organs adapted to the sense of
touch. Cats are unable to catch mice when these whiskers
are removed, and Rabbits without the assistance of their eyes
can by means of these hairs find an outlet in a very narrow
passage. In the Elephant this sense has its seat at the ex-
tremity of the proboscis. The wing of the Bat possesses an
extraordinary sensitive power. It is said that this animal is

740. What is said of the intuitive perceptions of the lo\rer animals ? T41. Where ia
the sense of touch most perfectly developed in animals ? Of what use are the •whiskera
of the cat and rabbit ? Where is the sense of touch in tha elephant ? -

404 HITCHCOCK'S ANATOMY

able to flj through perfectly dark and irregular narrow pas-
sages, and avoid all obstructions simply by the delicate sensi-
bility of its membranous wings.

742. Touch ill Birds.— The only portions of the skin in
Birds, on which tactile papillae exist, are found on the under
surface of the foot, and the web of the web-footed birds. The
bill of the Duck seems also to subserve the sense of toucli,
upon the inside of which the skin is soft, and has many
branches of the fifth pair of nerves distributed to it.

743. Toucll of Reptiles. — The sense of touch seems to
exist in Reptiles, though the prominent use of the skin is to
afford a protection to the body. It is quite probable that the
acuteness of this sense in these animals is no greater than
what is derived to the Horse through the hoof, or to a man
through a stick or rod in the hand.

744. Touch of Fishes. — Fishes probably have a still
more imperfect sense of touch than Reptiles. It is pos-
sible that the lips may give an imperfect idea of the form
of external objects ; but the surface of the body, covered
as it is with scales and a thick mucous secretion, can be
of no service in this sense. A few fishes have hair-like
appendages about the head, which put them in a condition
to be acquainted with the presence of external objects, though
they are not by any means organs of active touch.

745. Touch of Articulates.— This sense is well devel-
oped in all the Articulates, and shows itself especially in the
antennae, the palpi, and feet ; and though these organs have
a tough, hair-like consistence, yet they are efficient instru-

Where in the bat? 742. Where are paplllse found in birds? What answers the pur-
pose of papillag in the duck ? 743. What is said of the sense of touch in reptiles ? 744.
Where is the sense of touch located in fishes ? 745. Describe the sense of touch in &rtic^<
latea. .

ANI> PHYSIOLOGT.

405

menta of sensation. ^^^- ^^'^'

" For just as a blind
man judges of the
proximity and char-
acter of objects by
the impressions com-
municated to bis hand
by the contact of his
cane, with which he
examines them, so
may an insect or
crustacean receive
sensory impressions
from the nerves dis- ^ Foot of a riy.

tributed to the basal joints of their long antennae, although
the organs themselves may be as insensible (or rather as un-
irapressible) as the stick."

746. Touch of Molluscs. — The sense of touch in this
group is well developed. In some of the orders the organs
are from two to four contractile tentacles situated upon the
head, or the anterior part of the back." "With some Gas-
teropods these tentacles are hollow and button-like at their
extremity, and can be inverted like the finger of a glove."

747. Touch of Radiates.— ''The sense of touch is well
developed among the Echinoderms." It exists here and
among other Radiates in tentacles or feelers. Besides this,
other individual Radiates seem to possess a sensitiveness of
the whole surface of the body, though nerves can not be the
agents which secure this sense to them.

Is it by an active touch that this sensation is gained by articulates ? 746. Describa
touch in molluscs. 747. What ia the touch of radiates ?

im

HITCHCOCK'S ANATOMY

SENSE OF TASTE.

DEFINITIONS AND DESCRIPTIONS.

748. Anatomy of the Tong
nentlj the organ of taste. Its
Fig. 368.

Front View of the Upper Surface of the
Tongue, as well as the Palatine Arch. 1,
1, Posterior Lateral Half Arches, with the
Palato-Pharyngeal Muscles and Tonsils. 2,
Epiglottic Cartilage, seen from before. 3,
3, Ligament and Mucous Membrane, ex-
tending from the root of the tongue to the
base of the Epiglottic Cartilage. 4, One
of the Pouches on the Side of the Posterior
Fraenum, in which food sometimes lodges.
5, Foramen Caicum. 6, Papillai Capitata)
sen Maximae. 7, The white point at the
end of the line, and all like it, are the Pa-
pillae Fungi formes. S, Side of the Tongue
and Eugfe Transvers;e of Albinus. 9, Pa-
pilla) Filiformes. 10, Point of the Tongue.

uc. — The tongue is preemi-
principal part is made up of
muscular fibers which run in
various directions, although
thej run in similar directions
upon the opposite halves of
this organ. The tongue is
covered with a thick mucous
membrane, which contains a
large number of papillae simi-
lar to those of the skin, which
are of three kinds, the Filiform,
Fungiform, and Circumvallate.
The filiform are from one
thirty -sixth to one eighth of
an inch long, of a conical
shape, and are most abundant
on the middle portion of the
tongue. The fungiform are
situated upon the tip and sides
of the tongue, and are some-
what smaller than the filiform.
The circumvallate are from
six to twelve in number, and
are arranged upon the base
of the tongue in the form of
the letter V , the apex pointing
downwards. Thej consist of
a central round papilla flat-

743. What U the organ of tasto ? Of what is it made up, and with what Is It covered ?
Name th* th»e« kindg of p.ipill*. Deseriba the flliform, fungiform, and circumvallate.

AND PHYSIOLOGY.

407

tened at the end, one twenty-fourth to one twelfth of an inch
in diameter, with a lower uniform wall closely surrounding
the papilla. More nerves are distributed to the circumvallate
than to either of the other forms of papillae. At its lower or
posterior extremity the Pjp^

tongue is attached to
the OS hyoides, and at
its lower front portion
to the lower jaw by the
frsenum or bridle of
the tongue ; so that it
is left free to move ei-
ther backwards or for-
wards by the contrac-
tion of the appropriate
muscles.

749. Blood-Vessels of this Organ.— A great quantity of
blood-vessels are distributed to this organ, as can be seen by
looking at the under side of it, as well as by the free flow of
blood when it is wounded.

750. Nerves of Taste.— Of nerves there are no less than
three large branches supplied to the tongue from the cranial
group : the gustatory or proper nerve of taste, a branch of
the fifth pair which is distributed to the papillae ; the glosso-
pharyngeal distributed to the mucous membrane, being both
a nerve of motion and sensation ; and the hypoglossal distrib-
uted to the muscles, being preeminently a nerve of motion.

One of the smallest Papilke of the Tongue highly
Mascnifled.

FUNCTIONS.

751. Use of the Numerous Muscular Fibers in ihe
Tongue. — To effect the numerous movements of the tongue in

Which kind receive the most nerves? To what is the tongue attached by its lower
«ttremity ? 749. What proportion of blood is sent to this organ ? 750. How many nerves
are sent to the tongue, and what are they ?

18

408 HITCHCOCK'S ANATOMY

mastication,- swallowing, tasting, articulation, etc.
sarj that the muscular fibers should run in various directions.
That, however, which is commonly known as the tongue is
onlj the tip of it, while the largest portion lies in the front
and lower portion of the pharynx, where most of the muscu-
lar actions are performed.

752. Use of the Papillse.— The papillae of the tongue, as
those of the skin, are constructed for the purpose of giving
as much surface of nerve to be exposed as possible, leaving it
mostly in t e form of a loop. The filiform papillae are not
the seat of the sense of taste or touch, but are analogous to
the lingual spines of lowxr animals (which gives such rough-
ness to their tongues), which aid in mastication and protec-
tion of the tongue. As the sense of touch is most acute at
the tip of the tongue, it is supposed that the fungiform papillae
are the instruments of touch to the tongue ; and as we acquire
the sense of taste more at the base than at the tip of the
tongue, and as the nerves are more abundant and finest at the
circum vallate papillae, these probably administer mainly to the
sense of taste.

753. Object of this Sense.— The main use of this sense is
to direct us in the choice of proper articles of food, and by
this means to excite the flow of saliva and mucus, to aid in
digesting food. In man, however, this sense would be an un-
safe guide, since this alone can not aid us to distinguish whole-
some from poisonous food, although many of the lower animals
seem able to make such a distinction by this sense alone.

754. Effect of Education on Taste. — Taste is made won-
derfully acute by education. Epicures are able to tell the
manner in which game was killed, the spices used in cooking
it, and the length of time since it was killed, when eating it.

751. Why are tbore so many muscular fibers In the tongue? Where does the larger
portion of this organ lie ? 752. Of what use are the papillfe? What sensation is gained
liy the filiform papilla-? In what papillsB does the sense of taste mainly exist? 753.
"What is the u.sq of this sense ? Is it alone a safe guide for man? 754, Wliat effect has
edncation npon tasto ? Give Instaneea.

AND PHYSIOLOGY. 400

Wine tasters can readily give differences in the age, growth of
tlie grape, and the purity of wines, that to ordinary observers
are imperceptible.

755. Taste as Influenced by Smell.— Taste, as to some
substances, is dependent on the sense of smell. Thus, with
the eyes and nostrils closed, if an aromatic or spicy substance
be chewed it is impossible to say what the substance is, except
that it is pungent, although it may be one with which the per-
son is well acquainted. Yet smell does not aid us in deter^
minino- the taste of acids, alkalies, or salts.

756. A f t e r - T a s t e s . — An important point connected with
this sense is that known as after-tastes. Thus, frequently
after eating sweet substances a bitter taste is left in the mouth,
and when bitter substances have been tasted a pleasant an(^
sweet taste is left in the mouth. This subject is a matter of
great importance in the art of cookery.

THE SENSE OP TASTE IN ANIMALS.

757. Use of llie Conical Papilla;.— This sense is in aU
animals confined to the tongue and inner surface of the mouth.
The sensation received from the sapid body is gained through
the papillae, which are present on the tongue and in general
structure resemble those of the skin. There are probably
four kinds in mammals, those upon the central part of the
tongue often being conical, hard, and even horny, and those
upon the back part fungiform, or soft and cup-shaped, as is
seen in the tongue of the cat. The conical papillse seem to
act the part of a rasp, especially in the carnivorous animals,
in order to remove all the particles of meat from bones. And

755. Give the connection between taste and smell. 756. What is said of after-tastes?
757. How many kinds of papillae in most mammals? What are the uses of the conical
papillae to meat-eating animals ? How powerful an instrument do these at times consti-
tute ?

410 HITCHCOCK'S ANATOMY

SO efficient are these that the skin of some of the more deli-
cate animals is removed simply by the licking of the tongue
of one of the more powerful carnivora.

758. Tongue of Birds — In the Woodpecker and Hum-
mi ng-Bird. — In birds this sense is very feeble, since the
tongue is destitute of sensitive papillae, and is often of a hard,
horny consistence, designed probably more for the means of
obtaining food than of judging of its quality. In some birds
the tongue is furnished with one or more ossicles for the pur-
pose of giving stability and strength to it. In woodpeckers
the tongue is not only long, slender, and stout, but it is armed

Fig. 370.

Head of the Woodpecker.

with appendages like barbs on either side, in order that it may
be thrust into narrow crevices in trees, to pierce and hold in-
sects upon which it lives. (See Fig. 370.) Humming-birds
have tongues very slender and slit at the apex, so that both
sides can be formed into a sort of tube by curving them to-
gether from the outside, in order that the bird may suck
up the nectar of flowers. And in both of these birds the
tongue can be extended for a long distance in front of the
body.

759. Tongue of Reptiles — Chameleon. — The tongue of
most of the class of reptiles seems to be constructed for other
purposes than that of taste. Like that of birds, it is pro-
vided with one or more lingual (tongae) bones, and is desti-

753. How is It with the sense of taste in birds ? Describe the tongue of the woodpecker.
What is its use ? What is the tongue of the humming-bird ? How far can the tongue
be protrud&d in either of these animals? 759. For what purpose Is the tongue of rep*
tiles?

AND PHYSIOLOGY

411

tute generally of papillae. In some of this class it is hardly
perceptible, while in Serpents, Toads and the Chameleon, it
is very long and capable of rapid motion. In Chameleons and
Serpents, when the tongue is at rest, it lies in a kind of sheath
at the base of the mouth. That of the latter is forked at its
apex, while the former has a concave disk at its point covered
by a viscid secretion, which, by the dexterity of the animal,
can be thrown at once against the insects flying in the air,
thus securing its food. In this case also the tongue seems
longer than the body itself

Fig. 311.

Tongue of Common Fly. or, Lobes of Lingula. 5, Portion enclosing tho Lancets
formed by the Metamorphosis of the Maxilla, c, Maxillary Palpi, a. Portion of
one of the Metamorphosed Trache£c enlarged.

How does the chameleon obtain his insect food ? 760. Have fishes any tongue, or tho
sense of taste? 761. How well is this organ developed in some of the lower animals?
762. Describe the shape of the nose. Of what is it principally composed ?

412

HITCHCOCK'S ANATOMY

760. This sense in fishes appears to be very feeble. ''The
part named tongue in them consists merely of the anterior ex-
tremity of the tongue-bone covered by mucous membrane."
If fishes possess this sense, the palate rather than the tongue
is probably its seat.

761. Invertebrates. — Taste, doubtless, exists in all the
lower animals else how could they select their food ? The
seat of this sense is not always discoverable, as can be done
in the Cephalopoda. But the sense exists in all, even in the
Protozoa. Fig. 371 exhibits the tongue of the common fly,
which is doubtless the' seat of this sense.

SENSE OF SMELL,

DEFINITIONS AND DESCRIPTIONS.

Fig.

762. Anatomy of the N o s e .—The Nose which contains
the organs of smelling, is a triangular pyramid placed upon
the face, its apex connected with the forehead, and its base
descending nearly to a level with the upper lip. It is prin-
cipally made up of bone cartilage and integuments, having a

thin plate of bone (the vo-
mer) and cartilage in the
middle which run in a verti-
cal direction, and divide the
cavity into two portions called
the nostrils. (Fig. 372.)

A View of the Cartilages of the Nose.
1, The Nasal Bones. 2, The Cartilaginous
Septum. 3, The Lateral Cartilages. 4,
The Alar Cartilages. 5, The Central por-
tions of the Alar Cartilages which consti-
tute the Columns. G, The Appendices of
the Alar Cartilage. 7, The Nostrils.

AND PHYSIOLOGY.

413

Fig. 378.

762 a. Use of the Bones.— Use of the Cartilages,
and the Glands in Integuments.— The bones are the
two nasal, which give form to the base of the nose, and fur-
nish a firm attachment to the muscles. The cartilage is of
use to give form to the nose, while its elasticity lessens the
effects of injuries. The integument or skin is quite thick
upon this organ, and aids the cartilage in giving form to it.
It contains in its substance small glands, which secrete an oily
matter to protect the nose from extremes of weather. These
glands are liable to retain dust and other impurities in their
orifices, forming the black specks on the nose.

763. Lined wi.th Mucous Membrane.— The whole cav-
ity of the nostrils is lined with mucous membrane, which is
continuous with the lining membrane of the fauces or throat,
with which the nostrils are in communication.

764. Cavities of the
No strils . — Nerve of
Smelling — The cavities
of the nostrils are very
irregular, since upon their
own outer sides are found
the turbinal bones and
a similar scroll-like por-
tion from the ethmoid
bone, for the purpose of
giving as large a surface
as possible for the expan-

A Vertical Section of the Middle Part of the Nasal Fossae, giving a Posterior View of
the Arrangement of the Ethmoidal Cells, etc. 1, Anterior Fossa; of the Cranium. 2, The
same covered by the Dura Mater. 3, The Dura Mater turned up. 4, The Crista Galli
of the Ethmoid Bone. 5, Its Cribriform Plate. 6, Its Nasal Lamella. 7, The Middle
Si)on2y Bones. 8, The Ethmoidal Cells. 9, The Os Planum. 10, Inferior Sponsy Bone.
11, The Vomer. 12, Superior Maxillary Bone. 13, Its Union with the Ethmoid. 14,
Anterior Parietes of the Antrum Highmorianum, covered by its Membrane. 15, Its
Fibrous Layer. 16, Its Mucous Membrane. 17, Palatine Process of the Superior Maxil-
lary Bone. IS, Eoof of the Mouth, covered by tlie Mucous Membrane. 19, Section of
this Membrane. A Bristle is seen in the Orifice of the Antrum llijihmorianum.

762 a. State the use of bone and cartilage in the composition of the nose. Of -what ser-
vice are the little glands in its skin? 763. What are the nostrils lined with? 764. De-
scribe the cavities of the nostrils.

414 HITCHCOCK'S ANATOIIT

sion of the nerve of smell, and at the same time furnishing such
an arrangement, that the air containing the odor can be readily
drawn over it. This nerve is the Olfactory or first pair of
cranial nerves, which, as soon as it reaches the nostrils, is
divided into a great number of filaments, and these are dis-
tributed upon the mucous membrane — called Pituitary — al-
ready described. The fifth pair of cranial nerves also sends
branches to this membrane, by means of which it is that
sneezing is efiected.

765. Smell under the Control of the Will —The sense
of smell is somewhat under the control of the will, since the
air containing the odoriferous particles can be carried over the
nostrils or rejected at pleasure, and it can also be cultivated
to a great extent, although some persons are naturally more
sensitive to odors than others. It is related that a gentleman
who had a great antipathy to cats, could tell if there was one
in the next room by smell alone. And the blind boy Mitchell
always formed a favorable or unfavorable impression of a
stranger by this sense.

THE SENSE OF SMELL IN ANIMALS.

766. The sense of smell is most perfectly developed in air-
breathing animals, although many which live in the water, can
distinguish odors or scents to a considerable distance.

767. Smell in Mammals. — In Mammalia the mucous
membrane covering the turbinal bones is supplied with ol-
factive nerves. And in carnivorous animals, like the Lion
and Tiger, these bones are split up into several laminae, giving
them arborescent or tree-shaped forms, so that the membrane

Why arc tlio turbtnal bones placed here ? What is the nerve of smelling? 765. To
■what extent is smell under the control of the Avill ? What curious facts in this connec-
tion ? 766. In what animals is this sense the most perfectly developed ? 767. Among
Avhat mammals do we find this sense in the greatest perfection ? What peculiarity in
the turbinal bones in the lion ?

AND IBYSIOLOGT. 415

may be expanded over as great a surface as possible. Tho
cavities in the bones of the face and skull in these animals; as
Tvell as also the Horse and Deer, are very much developed,
and all the mammalia, except the Whale tribe, are supplied
with a turbinal bone, the cavities of which are lined by a
membrane which greatly aids in the sense of smell. The
sense of smell is also greatly developed in the timid grazing
animals, so that they may in this way receive notice of the
approach of their enemies and escape. For most quadrupeds
give off a strong odor from their bodies, in the exhalations of
the skin.

768. Smell in Birds.— A Nasal Gland.— Birds possess
turbinal bones and a large nasal cavity, but it is doubted
whether much of the power of discerning their prey de-
pends on this sense, or whether it does not entirely depend
on vision. For the olfactory nerve merely ramifies upon
a part of the nasal cavity, the remaining portion being sup-
plied with branches from the fifth pair. There is, how-
ever, a peculiar gland called the nasal, which serves the pur-
pose of lubricating the pituitary (or mucous) membrane, which
is probably necessary from the fact that so much air is con-
stantly passing over the nostrils that the membrane would
otherwise become dry and thus impair the sense of smell.

769. Smell in Reptiles. — Reptiles seem by their organiza-
tion of very simple nasal cavities, to have their sense of smell
feebly developed. A few only have bony or cartilaginous
turbinal organs, and a portion only have the cavities lined
by a pituitary membrane ; and from the gormandizing habits
of these animals, we see that the sense of smell could be of
but little service to them.

770. Smell in Fishes.— Fishes possess a cavity lined by a

What bone Is the whale tribe wanting in ? How is the sense of smell in grazing ani-
mals? 768. How well developed are the organs of smell in birds? What is probably the
case with regard to their powers of smell ? What gland is furnished to them which poF-
Bibly aids this sense ? 769. What is said of this sense among reptiles ? Is this sense of
any great vaiue to them ?

18*

41d HITCHCOCK'S ANATOMY

pituitary membrane and furnished with olfactory nerves, which
gives them a powerful organ of smell. This cavity, however,
has no posterior orifice, its only opening being in front, and
the water in it being continually kept in motion by the ciliae
with which it is lined. In the sharks and rays there is a mus-
cular appendage to keep the water in motion, so that Sir
Richard Owen says these animals must actively scent (that is
search for odoriferous impressions) as well as smell.

771. Artie 111 at a. — Crustaceans have the sense of smell,
and the central ganglion sends off an olfactory nerve. The
Arachnoids can smell without any discoverable organ. So
also the Insects. Probably all of the Articulates have this
sense, but perhaps without special organs.

772. Molluscs . — In Cephalopods olfactory organs are made
out, but not in the other classes.

773. R a (1 i a t a . — No distinct organs for this sense have been
found in these animals. But the presumption is that it exists
with or without special organs in them all.

Of the Protozoa the Infusoria clearly evince sensation and
volition ; but no nervous system has been discovered in them,
and though it is quite manifest that they are sensible to the
contact with objects and to light, yet there is no evidence that
they have the sense of smell. Equally probable is it that it
is wanting in the Rhizophoda.

HYGIENIC INFERENCES IN RESPECT TO THE SENSES.

774. — 1. Moderation in their Use Required.— All the
organs of sensation require to be moderately employed. If

770. How is it with the sense of smell in fishes? What peculiarity amon? the sharks
and rays? 771. Have articulate animals the power of smelling? Have they the or<rans
arlapted to it ? How is it probable that lobsters smell ? 772. Can shell-fish smell ? 773.
What of animals lower in the scale f

AND PHYSIOLOGY. 417

the eje be used in too strong light, weakness or partial pa-
ralysis of the optic nerve may be produced ; and if the ear
receive too violent a sound, deafness may follow, and so with
the other senses. Therefore care should be taken in the use
of the senses, for when the function of one of the nerves
of special sensation is gone, it is very rarely if ever restored.

775. — 2. Sudtleii Extremes of Sensations to be Avoided.
— With some of the senses, and especially that of vision, great
care must be taken to avoid, if possible, sudden transitions.
Next to very excessive use and mechanical violence, no greater
trial can be given to the optic nerve than a sudden contact
with powerful light. To a student this inference is of great
value, and especially to those who would rise early and study
by candle-light, before daybreak. This practice is often a
source of confirmed weak eyes. One reason is, that during
sleep the pupil is dilated, and when the eye is opened doss
not readily contract. This statement, however, is not an ar-
gument against early rising, which for other reasons has been
shown to be healthy to the student. A good rule for students
in sound health during the long nights of the year is to rise
before daybreak, and after washing the eyes in pu' e cold water
to take a good share of the exercise needed for the day.
Then, after an early breakfast, when food and exercise are
both obtained, he maybe ready for a day's work of hard study
by the congenial light of the sun. If, however, circumstances
are such that we must study in the morning by lamp-light,
we should commence and work moderately until the eye is
accustomed to the light.

775. a. — 3. Cleanliness of the Organs of Sensation ?Jcc
cssary. — Perfection of sensation requires that all the organj
should be kept clean. The eye needs occasional washing, not

T74. "Why do the senses all require moflcmtion in their "se? What if a nerve of special
Bcnse is destroyed? 775. What is said of sudden extremes of sensation? Why sliouLl
students especially avoid all extremes of light and darkness as far as possible ? How docs
early rising affect the eyes? 775. a. How does cleanliness affect all the organs of tho

.?

418 HITCHCOCK'S ANATOMY

rubbing, with cold water ; the ear not only needs the applica.
tion of cold water, but occasionally the careful use of the ear-
pick to remove the accumulations of wax which is gathered
beyond the reach of ordinary washing. If the nostrils are
buried by collections of snuff, how can we expect acuteness in
the sense of smell ?

776. — 4. Senses Need Education. — The senses need edu-
cation. No portions of the body show so well the good effects
of discipline and practice as do the organs of sense. The
power which, by training, can be acquired of distinguishing
the faintest shades of color, the slightest discord between mu-
sical tones, and of the quality and flavor of food and drinks
by the smell and taste, is so great as to astonish us.

777. — 5. Is Taste a Proper Guide for the Appetite?—
The question often arises whether the sense of taste can be
considered a safe guide for the appetite. As it is natural,
some maintain that it should always be gratified. But even
if originally safe to follow, how often has it been perverted by
extravagant diet, and is at the time in a morbid condition from
a perverted state of the body ? If such be the case, we should
be on our guard against indulging peculiar appetites, or strange
tastes. But in some cases, of which the physician is the best
judge, it may be safe to allow a reasonable indulgence in a
desire for a peculiar article of food or drink.

778. — 6. Our Senses Sometimes become Sources of Mis-
ery.— In such a world as this our senses, especially if exqui-
sitely cultivated, often become inlets of keen suffering. Ob-
jects disgusting to the soul must necessarily obtrude themselves
upon every one. Those who are afflicted with a dainty appe-
tite and are very nice and particular as to their food, often
suffer acutely ; while he who has learned to eat only that he
may live, instead of living only that he may eat, experiences

776. Do tho senses show the good effect of education ? 777. Is taste a suflBcfent guide
for the appetite ? What is said of peculiar appetites and tastes ? 778. Do our senses ever
give us pain ? In what way does a cultivated taste often make us wretched?

AND PHYSIOLOGY. 41D

gustatory enjoyment from the same food that turns the stom-
ach of another. True, a taste for the fine arts must be culti-
vated, although the sensorium will thereby be subject to pain
from discords in sounds, and incongruities in colors and forms.
But in respect to diet, regimen and manners it is hazardous
to cultivate the sensibilities till we become disgusted with al-
most every thing we meet, and make ourselves objects of ridi-
cule for our peculiarities.

779. — 7. A higher kind of Happiness than that de-
rived from the Senses. — Finally, we ought to remember that
enjoyment gained through the senses, is not the highest kind of
happiness for man. Thou h it be all, or nearly so, which the
brute can enjoy, yet the intellectual and moral powers of man
demand of him the control of his sensual desires, and a love
for that which is far higher and purer, For thus will all his
faculties be engaged in their appropriate sphere, and keep
bright till the end of life, and as its evening shadows steal
upon him, they will find him not full of disease and low de-
sires, but peaceful and happy, ready to make a change from
bodily to spiritual realities, almost without a sigh and with
exulting anticipations.

779. Is sensual happiness superseded hy no higher enjoyment?

CHAPTEE NINTH.

RELIGIOUS INFERENCES EROM ANATOMY AND
PHYSIOLOGY.

780. Highest Use of Science.— The highest and most
important use of all science, is its religious applications : since
these are eternal, while all its secular bearings are only tem-
poral.

781. Religious Yalue of Anatomy and Physiology. —
Perhaps no sciences are so prolific of religious applications as
anatomy and physiology. They bear especially and almost
exclusively upon Natural Religion.

I. PROOFS OF THE EXISTENCE OF GOD.

782. The argument for a Deity from marks of design so
obvious in nature, derives some of its most striking examples
from anatomy and physiology.

783. The Eye. — The eye has often been quoted as a strik-
ing instance. Who can mistake its object ? And when we
examine its structure, we see how admirably adapted all the
parts are — the coats, the media, and the nerve — to secure this
object. Arid it is done far more perfectly than by "the finest
optical instrument of man's construction.

784. The Ear. — -In the ear we have another example al-
most equally striking, except that the special object of some
of its parts is not so obvious as in the eye.

785. Hands, Lungs, Heart, etc. — Wc might say the
same of the hands and the feet, the lungs, the muscles, the

ANATOMY AND PHYSIOLOGY. 421

nerves and the heart. If design is not manifested in their
construction, it is difficult to see how they could be mani-
fested. The mechanical arrangements and operations of the
different parts of the system teach the same lesson.

786. Skeleton.— Spinal Column.— Take the bones of the
skeleton for an example. How admirably are these arranged as
a solid framework, around which the soft parts of the system
may be built up ! The vertebral column is not a single
straight tube, as our wisdom would probably think to be the
safest and best as a protection to the spinal cord within, but it
is made up of over thirty bones separated by an elastic sub-
stance, yet locked together and fastened by strong ligaments,
so as in fact to be stronger than a single piece, and moreover
it is made somcAvhat crooked, so that it will yield a little
when jarred, and thus prevent the brain from being injured.

787. Joints.— The joints too, how admirably fitted for the
manifold movements we need to make ! How securely fastened
together by numerous strong ligaments ! How much more
effectually lubricated by the synovial fluid than the most per-
fect engine of human construction ! Then again, how exactly
fitted to the parts of the body, in which they are placed, are
the different kinds of joints, the ball and socket, the hinge,
the sutures, etc. !

788. Muscular Arrangement.— Their Mechanical Dis-
advantage, etc. — Contraction — Perhaps even more striking
are the character, position, and mode of action of the muscles.
Always in pairs, except where a single one is all that is needed;
being antagonistic only where antagonism is wanted ; being thick
where great strength must be exerted, or some cavity must bo
fillod to produce symmetry of form ; being thin where wide
suTfaces were to be covered, or a proper proportion could not
be secured between the different parts of the body. Then how
wonderful that the great mechanical disadvantage, at which
muscles act, which at first sight seems so obviously a defect

422 HITCHCOCK'S ANATOMY

of arrangement, should on reflection be found wisely adapted
to our wants and comfort. The mode in which the muscles
act by mere contraction, is the simplest possible ; yet when we
inquire how this is effected, we find ourselves in contact with
some of the profoundest and most difficult of all subjects :
there is not only design, but unfathomable wisdom here.

789. Harmony of Chemical and Vital Agencies. — The
conjoint operation of chemical and vital agencies in building
up and perfecting the system, and freeing it from impurities,
is another marked example of design. These agencies, the
chemical especially, are blind, and we might expect that they
would as often destroy as they would preserve. But though
they are incessantly at work all over the system, as if it were
a busy laboratory, in building up the tissues, in converting
elements into immediate principles, and in separating and
casting out of the body the superfluous and deleterious mate-
rials, all goes right till Providence permits disease or accident
to disturb the harmony between vitality and chemistry, and
from the disastrous effects of their morbid action, we learn
how wisely ordered was their healthy operation.

790. Special Arrangement exhibiting Design.— There
are some special contrivances and arrangements in the animal
frame, which strikingly show design, because it looks as if
the Author of Nature had made a modification of his plan
to meet exigencies. Take a few examples.

791. Looped Muscles. — Look at the looped muscles.
There the tendon is fastened by a loop, in order that the
direction of the force, applied in contracting the muscle, may
be more or less changed, made in some instances, as in the
•oblique muscle of the eye, to pull in an opposite direction ;
or at right angles, as when the digastric muscle draws down
the chin.

792. Anastomosis of Blood-Vessels.— Then there is the
inosculation of the blood-vessels. How obviously this is in-

AND PHYSIOLOGY. 423

tended as a security, when some of the blood-vessels are
wounded and can not transmit the blood. It then seeks those
side channels, and soon thej so enlarge as to give free passage
to all the blood that is needed, even though a large vessel has
been closed. If man had constructed a machine with such an
arrangement we should have been sure what was the design.
Why doubt the same in respect to God's work ?

793. Protection of Large V e s s e 1 s .—Again, the large
blood-vessels and nerves are placed deep in the system, and
where they pass by prominent joints, grooves, or tubes, are
made for them ; or where one side of a joint is exposed to
injury and the other comparatively secure, the important ves-
sels are grouped together on the less exposed side, as in the
groin and arm-pit.

794. Annular Ligaments.— Take, for another example,
the annular ligaments around the wrist and ankle. Who can
doubt that they were placed there to prevent the tendons of
the muscles from starting out of their places, when the mus-
cles are strongly contracted and the feet and hands bent ? If
so, who can doubt that a Being of infinite wisdom devised and
executed this arrangement ?

795. Nervous Power . — But all this wise disposition of the
parts of the body might have been made and yet the whole
have been useless, had not some vivifying force been added.
Therefore the nervous system was contrived and incorporated
with every part of the body, commencing with the brain and
ramifying to all the extremities. It needed, too, a central
power to direct and control the nervous energy, and therefore
the mind, an immaterial and immortal principle, was enthroned
in the brain. From thence, as along so many conducting
wires, and doubtless by means of galvanic agency, it sends out
its orders to originate and control every muscular movement
and keep in play every function of the body. The nervous
system, then, is the mysterious connecting link between mind
and matter, and the admirable manner in which it performs its

424 HITCHCOCK'S ANATOMY

functions and enables the thinking principle to manifest its
astonishing powers, shows the nervous system to be the most
wonderful of all the contrivances which Infinite Wisdom has
placed in the human body. What could demand an Infinite
Deity if such a contrivance did not ?

796. Dependencies of one System upon Another.— The
connection between mind and body, however, is only imper-
fectly understood, and therefore there is one other thing which
exhibits more impressively than the nervous system and the
mental powers the agency of an infinitely wise Being. The
human body is made up of quite a number of minor systems
of organizations apparently independent of one another, yet_
all in fact mutually dependent and combined into one complete
and perfect system, with the parts all exactly adapted to one
another. Could any thing less than Infinite Wisdom have
accomplished so marvellous a work ?

797. The same Plan Exhibited in the whole Animal
Kingdom . — ^Yet if we extend our researches through the whole
animal kingdom, we shall find that this same mutual adapta-
tion and correlation extend through the whole series, so that
all are but parts of a mighty whole. From man downwards
through the hundreds of thousands of species, to the humblest
animalcule, each occupies a fitting place, and every link of
the long chain is in perfect harmony with all the rest, so that
the skillful anatomist, knowing one part of the chain, can
delineate the rest, just as a single bone of an animal often
determines the character of its whole frame. What vast
reaches of thought, what wonders of wisdom, what boundless-
ness of power must it have required, to weave together so vast
and varied a system into one golden web of harmonies !

II. PROOFS OF DIVINE BENEVOLENCE

798. All Organs and Functions Normally Produce
Happiness, — One proof of Divine benevolence is, that all the

AND PHYSIOLOGY. 425

organs and their functions are adapted to promote the welfare
of the individual. They may incidentally result in evil ; but
the object was to produce happiness. One object of the ner-
vous system was to guard us against injuries by putting us
on our guard against them. But in case of injury or diseased
action, intense* suffering often results ; and while enduring it
we are apt to forget the grand object of the nerves of sensa-
tion, and imagine incidental to be intentional evil. So carni-
vorous teeth and poison fangs are intended to provide animals
with food and the means of defense. But they may produce
great incid.ental evils by being used as animals have the power
to do, and are sometimes incited to do, aside from the normal
objects for which they were given. Indeed there is no organ
or operation whose leading object is not the production of hap-
piness ; and therefore we infer the predominant disposition of
the Author of nature to be benevolent.

799. Pleasure Superadded to Functious when not Re-
quired.— A second fact leading to the same conclusion is, that
often pleasure is superadded to animal functions, when it is
unnecessary to their perfect performance. It was not neces-
sary to perfect vision that the colors in nature should be
agreeable ; that the earth, for instance, should be green, or
that colors in flowers should be harmoniously blended. It
was not necessary for the support of the system that gusta-
tory enjoyment should accompany the reception of food ; for
severe hunger would have been sufficient to impel us to eat,
even thoug^h suffering; followed. And so in a thousand other
instances that might be named. On the other hand, no exam-
ple can be founi where unnecessary pain attends functional
operations. The Author of such a system must be benevolent.

800. More Modes than One Provided for the same Func-
tions.— A third evidence of benevolent design in the Author
of the animal system is the provision often made of more than
one mode for the performance of important functions. In the
act of swallowing, for instance, the danger is great that par-

426 HITCHCOCK'S ANATOMY

tides of food may pass into the lungs. Hence not only is the
epiglottis provided to close upon the glottis like a valve by
the very movement that carries down the food ; but the glottis
itself is endowed with such extreme sensibility that it instantly
closes upon the approach of a foreign body. The inosculation
of the blood-vessels has already been described, furnishing a
double means of circulation as a resort when one fails. We
might also refer to the two cerebral hemispheres, two lobes to
the lungs, two eyes, two hands, and two feet, so that the loss
of one does not obliterate the function. All this certainly
looks like the benevolent provision of a kind parent.

801. Surplus or Reserve Power. — And so, in the fourth
place, does the surplus power given to the organs for exigen-
cies above what is necessary exhibit benevolence. In the
muscles there seems to be no limit to this excess of force, save
in the ability of the fibers to endure the strain. The digestive
organs are capable of mastering a much larger amount of food
than is necessary, and the secretory organs at times give out
a much larger than the normal quantity of their peculiar prod-
ucts. If it were not so, life would be sacrificed in thousands
of instances where now the use of the surplus power preserves
it. If God is not benevolent how happens it that this special
provision for exigencies should always promote the welfare of
animals ?

802. Y i c a r i 0 u s Power .—In the fifth place, the vicarious
power given to some of the organs teaches the same lesson.
When one or more of the senses is destroyed or defective, the
others can often, in a good measure, supply their place :
touch, for instance, the place of seeing and hearing. So,
also, it is said when the glands appropriated to certain secre-
tions are injured or destroyed, others whose normal secretion
is quite difierent, can elaborate the principles ordinarily given
out by the injured ones.

803. Adaptation of Organs to Different Circumstances.
— The power of all the organs to adapt themselves to different

AND PHYSIOLOGY. 427

circumstances is a sixth example of benevolent intention in the
Author of nature. The range of this power is limited ; and
yet we are often surprised to what widely different conditions
We can be accustomed, and yet be comfortable in them by new
habits. In such a changing world as this is, such a power
seems almost indispensable, and yet only infinite skill could
attach it to organs which are controlled by inflexible chem-
ical and vital laws. Malevolence surely never would have be-
stowed it.

804. Recuperative Power.^ — The recuperative power of
the animal system furnishes us with a seventh example of
benevolent provision by the Creator. However deeply acci-
dent or disease may have affected the system, if the vital pow-
ers be not destroyed, it is possible frequently to bring it back
again to a state as sound and vigorous as before. The records
of pathology and surgery furnish most astonishing cases of
such restorations. And since accident and disease are so com-
mon, that scarcely any adult can boast of immunity from
them, what a sad picture would society present of cripples and
invalids, were this recuperative power wanting. It would be
just such a picture as infinite malevolence would delight in.
Its opposite therefore indicates benevolence.

805. Prospective Benevolence. — One other example only
will be given, and that may be called prospective benevolence.
Wasps and some other insects have an instinct which leads
them to deposit along with their eggs a supply of food for the
young insects when they are hatched, sufficient to nourish
them till they are old enough to take care of themselves. In
other animals nature provides a supply of milk to be ready
just at the time when needed by the progeny. The adulfc
man needs a firmer set of teeth than the in "ant, and so the
germs of these are placed beneath the earlier teeth, and these
at the proper time push their way upward, and crowd the
first set out of their sockets. In such cases the wants of
animals were anticipated by their Creator, just as a be-

428 HITCHCOCK'S ANATOMY

nevolent parent provides beforehand for the future needs and
happiness of his children.

806. — III. ANATOMY AND PHYSIOLOGY FURNISH PRE-
SUMPTIVE EVIDENCE THAT THE WORLD IS IN A FALLEN
CONDITION.

807. Benevolence blended witli Pain. — Wo have shown
that benevolence decidedly predominates in all the organiz^i-
tion and functions of the animal system. But it is not un-
mixed benevolence, as we shall now attempt to show. There
are evils connected with our physical condition, such as we
can not suppose would exist in a paradisaical state, and the
inference u that these evils are best accounted for by the sup-
position that the world is adapted rather for a fallen than for
a holy being. Let us look at some examples of evils which
we can not suppose a Being of Infinite Benevolence and
Power would connect with a state of perfect holiness.

808. The Nerves much move Sensitive tliaii is neces-
sary to Protect . — 1. , The nervous system produces suffering
far beyond what is necessary, to put us on our guard against
accidents and injurious agents. To awaken and cultivate
such prudence in respect to these evils, seems obviously a
leading object of p?in and suffering : for the nerves are most
abundant and sensitive at the surface of the body. But in
many diseases the suffering is intense. Indeed, exasperated
and maddened nerves produce the very climax of human
anguish. But some other object besides awakening a salu-
tary caution against evil must be in view by such suffering.
Now we know, that as a matter of discipline for a depraved
and sinful being, it is eminently salutary. It affords there-
fore a presumptive proof that such is man's character.

809. ImpossibiHly of avoiding Accidents and Disease,
— 2. Man's exposure to accidents and diseases, which no
human foresight cin avoid, leads to the same conclusion.

AND PHYSIOLOGY. 429

810. That he is thus liable, we need not attempt to prove,
because all will acknowledge it. But why should he be so
exposed under the government of a Being of Infinite Benevo-
lence, if there were not something in his character which de-
manded this severity of discipline ? What can .that be but an
alienated, rebellious heart, which no milder means will subdue ?

811. Evil incidental to every Function.— 3. Evil is
incidental to the functions of every organ in the body. Vision
exposes us to be witnesses of many most unpleasant scenes
and objects, hearing to sounds most grating, taste and smell
to odors and solids disgusting and poisonous ; locomotion
makes us liable to fatigue and bodily injuries, and disease es-
pecially assails every organ. We can not conceive these in-
cidental evils to be necessary in a world of perfect purity and
happiness. But they are wisely adapted to a fallen being, and
therefore the presumption is that man is in such a fallen state.

812. — Universality of Death.— 4. The existence and uni-
versality of death lead to the same conclusion.

813. It may indeed be made probable that in such a state
of things as the present, death is a blessing even to the inferior
creatures. But it would not be so in an unfallen paradisaical
state. It must be an immense drawback from the happiness
of such a state. It is, however, a fit and probably an inevit-
able concomitant and consequence of sin. Where it is uni-
versal, therefore, the presumption is that it is a fallen state.

814. Condition of Man not without Bright Prospects.
— 5. Bat though anatomy and physiology present so many
proofs of man's fallen condition, yet the evidence already ad-
duced that benevolence vastly predominates, affords to the
student of natural theology a strong presumption that it is
not a hopeless condition. For if there was no such thing as
recovery, why so many tokens of kindness ? Why not give
up the offender at once into the hands of j ustice, and let the
work of retribution commence? How the recovery might bo
effected revelation alone could show.

430 HITCHCOCK'S ANATOMY

Objection.— It is said that these arguments would prove the inferior animals, even those
that lived long before man, to be in a fallen condition, since they both suffer and die.

Answer. — The lower animals, not having a moral nature, cannot sin ; but they may
Buifer in consequence of their connection with sinful man. The world, from the beginning,
was adapted to him as a fallen being, and of course all other animals must be subject,
like him, to suffering and death. This sympathy of all nature with man's fallen condition
is clearly taught in Revelation. (See Rom. viii., 18-23.)

815. IV. ANATOMY AXD PHYSIOLOGY FURNISH PROOF OF

THE DIVINE UNITY.

That is, they show that only one Mind could have been
concerned in the plan of animal organization.

816.— 1. The Conspiration of all the Parts to Produce
the Same End. — This appears, in the first place, from the
conspiration of all the tissues and organs to produce a single
result. There are as many as a million of parts in the hu-
man body, all of which must go right to keep the system in a
healthy state. It may worry us when some of them go wrong,
as in case of disease ; but if many of them become deranged
death ensues. An attentive observer of the race will see that
all these parts are originally arranged so as to conspire in the
production of health and happiness. There could have been
no divided counsels in such a work.

817.— 2. Relations of Different. Individuals in the
Animal Kingdom.— The relations of all the branches and even
individuals of the whole animal kingdom to one another af-
ford a still more striking evidence of divine unity. For here
the objects to be compared are multiplied a thousand fold, and
the extremes in organization, in habits, and modes of living
are immeasurably wide Yet there is such a relation among
them all as to show them all belonging to one system, bound
together in the closest harmony. All must, therefore, have
been the work of one Infinite Mind. Or if more than one
was concerned, each must have had the same plan ; and the
idea is absurd that there can exist more than one infinite
mind.

AND PHYSIOLOGY, 431

818. — V. ANATOMY AND PHYSIOLOGY DISPROVE THE ATHE-
ISTIC HYPOTHESIS THAT THE DEVELOPMENT OF ANIMAL
ORGANS IS THE RESULT OF MERE LAW,

819. The Development Hypothesis,— -This hypothesis sup-
poses that the organs were not contrived and constructed by
an intelligent mind for the uses to which they are applied, but
that the wants of the living mass of almost amorphous matter
led to such efforts as ultimately to form an organ. Thus the
desire for food in a mass of vitalized jelly caused it to pro-
trude certain points which ultimately became hands, and the
desire of locomotion formed the feet and legs. To form the
organs in this manner it would be necessary that the use of
parts of the living unorganized mass or body should have a
natural tendency to produce them. If then we can show that
in some cases this tendency would be exactly the opposite, the
hypothesis must fall. We need give only a few examples to
show that such is the case. Take the looped muscles, such as
those in the back of the eye. Any effort of matter behind the
eye to move the ball must draw in a direct line, not in the
round about course of a loop attached to the orbit. Take the
case of the annular ligaments at the wrist and ankle. The
conatus of the muscles to move the fingers and toes would
tend to destroy but not to form such a ligament. They are as
obviously intended as any thing can be to counteract the con-
atus of the tendons to fly off when the muscles contract.

820. Such facts so manifestly show the absurdity of the
hypothesis under consideration, that examples need not be
multiplied. It is true of nine tenths of the organs, that an
effort of vitality to perform their functions before their exist-
ence would have a tendency the opposite of their formation.

19

432 HITCHCOCK'S ANATOMY

821. — VI. ANATOMY AND PHYSIOLOGY SHOW THE UNREA-
SONABLENESS OF OBJECTING TO MYSTERY IN RELIGION.

822. Any objection against religion that "will lie with equal
force against the constitution and course of nature is futile.
For none but the atheist will deny that nature is the work of
God, and it is not reasonable to object to that in religion
which we allow to exist in nature. But the cases of mystery
in anatomy and physiology are more striking than in religion.
A few examples will suffice.

823. — 1. Muscular movement. We can see that muscles
contract, but the power that does it is concealed. We find
that this power comes from the brain through the nerves ; but
this does not show us how the work is done. We find that
electricity is concerned ; but why should electricity contract a
muscle more than a wire ? This carries us to the end of our
knowledge, and still we know nothing of the nature of that
force by which the will is able to move a muscle. The whole
range of science gives not the slightest clue to the mystery.
It is, in fact, as profound as any in natural or revealed relig-
ion, and until we can solve this we have no right to object to
any religious doctrine on the ground of mystery.

824. — 2. The entire connection between mind and matter
teaches the same lesson. When we have stated the facts as
to their mutual influence, we have nearly reached the limit
of our knowledge of the subject. There is no physical law
or mental law either that can explain their action and reac-
tion. All attempts to do this amount to little more than the
vaguest hypothesis. Any thinking man who studies the phe-
nomena will be impressed by the mystery that hangs over
them, and if he be a true philosopher will be slow to reject
any doctrine of religion because it has depths in it which he
can not fathom.

INDEX AND GLOSSARY.'

The numbers refer to t7u page.

A.

Aboma'sam, 186, 187.

Abdom-'inal muscles, 125.

Abdom-'inal aorta, 211.

Abdu'cent nerves, 329.

Acale'phi, one ol the groups ofj radiate

animals.
Access'ory heart, 233.
Aera'tim, purifying by air.
Afferent, carrying to.
After tastes, 409.
Air, amount used in breathing, 253.

" " of in lungs, 256.

Alhu'men, a proximate principle, 12.
Albu'minose, 12.
Algae, sea weeds.

Ambuldtory, pertaining to a walk.
Amor'phous, without shape.
Amphiarthro'sis, 66.
Anastomo'sis, 202.
Anat'omy, definition of, 5.

" Comparative, definition of, 6.

An'chylosed, grown together.
Anfractuos'ities, depressions on the brain.
Angiol'ogy, 201.
Angular motion, 68.
Animal heat, theory of, 258.

" kingdom, classification of, 84, 85.
Animal'cules, minute animals.
An'nular, like a ring.

" ligaments, 132.

Antisep'tic, preventive of decay.
Aor^ta, 206.

" in animals, 231.
A'pex, point or summit.
Aponeuro'sis, 110.
Appendages of cells, 18.
A'queous humor, 374.
Aquiferous, water bearing.
Arach'noid membrane, 324.
Ar'senic in the body, 7.
Arterialization — ^see Aeration.
Arteries, 204.

" and veins, comparative capacity

of, 223.
Arthro'dia, 67.
Articula'ta, 85.

" skeleton of, 103.

Artic'ulate, to make a joint.
Artlevla'tion^ joints.

" varieties of, 66.

" anatomy of; 67.

AssimiWtion, conversion of matter into

the substance of the body.
Atmospheric pressure in joints, 71,
Audi'tion, hearing.
Au'ditory nerves, 329.
Au'ricles, 201.
Automatic, acting apparently without the

will.
Ax'illary artery, 206.
Azofic, containing nitrogen.
Az'otised, containing nitrogen.

Back Board, 144.
Basement membrane, 17, 298.
Beaded, like a string of beads.
Belief, effect of on sensation, 368.
Belly of muscles, 109.

Benevolence, Divine, shown by anatomy,
424.
" prospective shown in organs,

427.
" blended with pain, 428.

Biceps muscle, 119.
Bicus^pid teeth, 54.
Bile, 16, 175.
Bill of birds, 96,189.
Birds, rate of flight, 154.
Blaste'ma, 20.
Blood, 15, 220.

" of articulates, 241.

" vessels, their use, 222.

" " " large amount, 22S.

Body, its size, 10.
Bones, chemical composition of, 81.

" mechanical structure of, 82.

" classes of, 35.

" strength of, 32.

" microscopic structure of, 83.

" intermax'illary, 89.

" jugal, 93.

" cor'acoid in birds, 96.

" sternal " '• 96.

" tarso-metatarsal, in birds, 97.

" sesamoid, " " 8T.

" development of, 36.

" number of, 37.

" uses of, 74.

" distorted, reason of, 81.

" effect of wrong position on, 8S.

" hollow in birds, 98.
Brachial artery, 206,
Bra'chial plexus, 834

434

INDEX AND GLOSSARY.

Brain, 318, S42.

" of mammals, S57.
Breathing, object of, 253.
Bronchi, 250.

" of mammals, 270.
Bronchi'tia, inflammation of the Bronchi.
Brunner's glands, 163.

Coecal cells, closed or shut sacs.

Caecum, 161,

Calca'reona, hard like limestone.

Cal'cified, made hard like limestone.

Cal'cium in the body, 7.

Calisthen'ics, 141.

Callos'ities, 811,

Calcutta, blackhole of, 266.

Calorific, heat producing.

Canalic'uli of bones, 33.

Ca'nine teeth, 54.

Cap'illaries, 214.

Car'apace, 99,

Carbon in the body, 6,

" its amount given off from the

lungs, 255.
Carbon'ic acid in the body, 10.
Carniv'orous, flesh eating.
Carot'id artery, 206.
Carpus, 59, 78, 91,
Cartilage, invertebral, 42.
Cartilag^inotLS, made of cartilage.
Ca'sein, 12.
Caudal heart, 238.
Cells, 18.

" vital force of, 21.

" chemical changes of, 21.

•• vitalization of, 21.

" change of form, 21.

" periods in the life of, 21.
Cellular, having cells.
Cemen'tum, 51.

Centrip'etal and centrif'ugal, 349.
Ceph'alopod, a molluscous animal.
Cerebellum, 319, 347.
Cer'ebral ganglia, 321, 348,

" hemispheres, use of, 341
«» nerves, 358,
Cer'ebro-spinal center, 322.
Cer'ebrum, 318.

" of mammals, 357.
Cer'vical plexus, 334,
Chem'ical elements of the body, 6,
Chem'istry and vitality combined show de-
sign, 422,
Chi^ine, 84, 314.
Chit''inous, containing chitine.
Chlorine in the body, T.
Cho'roid coat, 871.
Chyla'queous fluid, 241.
Chyle, 15, 180.
Choles'terine, 11.
Chyme, 175.
Cil'im, minute hairs.
CiKiary processes, 871.
Circle of Willis, 210.
Circula'tion in molluscs, 242.
" in radiates, 243.

Circtvmduc'tion, 68.
Clav'icle, 57, 78, 96.

Cloa'ca, a sac appended to the Inteatlnes.
Ck>ag'vXable^ capable of hardening.

Coats of the eye, their use, 378.

Coch'lea, 391.

Coc'cyx, 41.

Coeliac axis, 212.

Colds and Coughs, 268.

Colon, 162.

Color blindness, 383.

Compound eyes, 386.

Cona'tus, attempt.

Con'diments, their use and abuse, 184.

Con'dyle, elevation or eminence on a bone.

Con'voluted, rolled together like a tube.

Coordina'tion, working or designing to-
gether.

Copper in the body, T.

Cor'acoid bone, 96.

Coria'ceous, like leather.

Co'rium, 298,306.

Cor'nea, 870.

Gor'neous, like horn.

Cor'pora stria^ta, 322.

Cor'pusclts, little bodies or cells,
ofblood, 220,228, 254.

Corpulence, its efi'ect on capacity of lungs
254.

Corpus callosmm, 819.

Cra'nium, skull.

Cra'nial nerves, 825-331.

Cremation, 9.

Cric^'oid cartilage, 260.

Crusta'ceans, animals like the crab and
lobster.

Ctenoi'dians, 314.

Cubical size of the body, 10.

Cune'iform cartilage, 260.

Cuta'neous, relating to the skin.

Cu'ticle, 296,

CycloiMians, 814.

Cytogiii'esis, cell production.

D.

Daily water bath, 810.

Daltonism, 383.

Death universal, 429.

Decussa'tion, crossing like an X.

Degluti^tion, 172.

Deity, argument for, from anatomy, 420,

Den'tine, 51.

Denti'tion, appearance of teeth.

Den'izen, an inhabitant.

DermatoVogy, science of the skin.

Dermis, skin.

Development hypothesis, argument against,
431.

Development hypothesis, disproved bj an-
nular ligaments, 481.

Diarthro'sis, 67.

Di'aphragm, 124, 150.

Dias'tole, 226.

Diet best adapted for man, ITT.

Digas'tric muscle, 116.

Diges'tion, its theory, 1T4, 175. ^

Dip'loe of cranium, 76.

Disassimila/tion, process of wast*.

Disease not to be avoided, 428.
" of circulatory organs, 228.

Dorsal vessel, 239.

Duode'nal glands, 163.

Duode'num, 160.

DtipHca/tive folding or doabllng.

Dura mater, S23.

INDEX AND GLOSSARY.

435

E.

Ear, 889.

" a proof of design, 420.

" functions of all its parts, 394, 397.

" of animals, 297, 399.
Eating, hygienic inferences from, 183, 184.
Echin'oderms, radiate animals.
Efferent, carrying away from.
Electrical organs of fishes, 360.
Elemen'tary tissue, 14.
Einacia'tion, wasting away.
Enam'el, 51.
Enarthro'sis, 67.
EnMosmose, 17.
Epider'mis, 296.

" use of, 305, 806.

Epifler^mic scales, 311.
Epiglot'tis, 261.

Epithe'lial, relating to the epithelium.
Epithe'liinn, outer surface of mucous and

other membrane.
Esoph'agus, 157.

" of horse, 186.

Eusta'chian tube, 891.
Evil incidental not intentional, 425.

" " to every function, 429.

Excrementi'tious^ waste or superfluous.
Ex'osmose, 17.

Extremities, anterior, of quadrupeds, 92.
Exudii'tions, 15.
Exu/via'tion, casting off.

" of serpents, 313.

Eye, anatomy of, 369.

" a proof of design, 420.
Eyebrows, 376, 380.
Eyelids, 376, 380.
Eyes of mammals, 383.

" " birds, 384.

" " reptiles, 386.

" " fishes, 386.

" " insects, 386.

" " mollusca, 388.

" " radiata, 388.

F.

Fac'et, a little surface or face.

Face, 47.

Fa'cial nerves, 329, 351.

Fats in the body, 11.

Feathers, 312.

Fel'on, 35.

Fera'oral artery. 212.

Fe'mur, 63, 79, 97, 100.

Fever sore, 35.

Fiber, simple, 17.

" muscular, 107.
Fi'bril, " 107.

" in contraction, 137.
Fibrin, 12.
Fib'ula, 63.

Flu'orine in the body, T.
Fol'licles, 289.

" of Lieberkuhn, 168.
Food< for what purposes required, ITfi.
Foram ina of bones, 85.
Forces of blood circulation, 228, 226.
Fore arm, 58, 78.
Fright, effect of on hair, 815.
Frontal bone, 43.
Functions, the mode for their performance,

425.
jN/aiform^ epindle shaped.

G.

Gall-Bladder, 165.

Gang'lia, small knots or masses of nervous

matter.
Ganglia, uses of, 350.
Ganoid^'ians, 314.
Gastric luice, 15, 173.

" follicles. 159.

" artery, 212.
Ge'nus, a group of species.
Gills of Fishes, 274.
Gin'glymus joint, 67.
Giz'zavd, second stomach of fowls.
Glands, their anatomy, 289.

" ductless, 292.

" of the skin in mammals, 812.
Gliding motion, 68.
Glob'ule, spherical particle of matter.
Glob'uHn, 12.

Glosso-pharyngeal nerves, 330, 851.
Glu'ten, 12.
Glu'teus muscle, 128.
Gompho'sis, 66.
Granules of cells, 18.

" " bone, 34.

Gymna'sia, their use, 141, 144.

H.

Habit, effect of on sensations, 368, 402.
Hair, number and distribution of, 303.

'* chemical composition of, 303.

" constitution, color, and properties off
304. ^ ^ '

" rate of its growth, 305.

variety of, in mammals, 811.
ffdm-^ter, a rodent animal.
Happiness the object of all organs, 424.
Harde^rian gland, 283.
Harmo'nia, 66.
Haver'sian canals, 33.
Head of birds, 93.
Heart of man, 201.

" " mammals, 230.

" " birds, 232.

" " reptiles, 234.

" " crocodile, 236.

" " fishes, 237.

" " articulates, 239.

" " Crustacea, 241.
Heat producing organs, 256.
Hem'atin, 13.
Hepatite, pertaining to the liver.

" artery, 212.
Herhiv'orous, vegetable eaters.
Bexag'onnl, with six sides.
Hippu'ric acid, 9.
Hiss of serpents, 272.
HUtogenePic, tissue making.
HistoVogy, 14.
Homogefneous, o{ the same characie?

throughout.
Honey comb, 187.
Horn of rhinoceros, 811.
Hu'merus, 67. 91, 97, 100.
Humors of the eye, 874, 878.
Hy'drogen in the body, &
HygroKbgy, 14
Hyoid bone, 55.

436

INDEX AND GLOSSARY

Ichorol'ogy, definition of, 282

Il'iac arteries, 212.

li'iiun, 61.

Imbibi'tion, 17.

Im'bHcated, overlapping like shingles on

a roof.
Iratne''diate principles, 7.
Imparities exhaled from lungs, 255.
Inci'sor teeth, 54.
Indian club, 145.

Infuso'ria, microscopic animals.
Ingiu'vies, ISS.
Innoinina'tum, 61.
InosauUi'tion — see anastomosis.
Inspirations compared with pulsations, 355.
Interartic'ular cartilage, 71.
Intercos'tal muscles, 125.
Intermax'illary bones, 89.
Inteross'eou.% between the bones.
Intes'tinal fluid, 16.

" glands, 163.
Intes'tine, leniith of, 155, 1S9, 192.
Inver'tebrate, without internal skeleton.
Iris, 371.

Iron in the body, 7.
Irritability of muscular fiber, 134.
Is'chium, 61.

Jeju'num, 161.

Joints, design shown in them, 421.

" motions of, 68.
Jugal bone, 93.

Kidneys, 171.

L.

LaVyrinth, 391.
Lach-'rymal gland, 375.

" bones, 49.

Lac'teals, 169, ISO, 282.
Zacn^nce, spaces.

" of bone, 33.
Lacu'nar, filled with lacunse.
Lamell'(je, thin laj^ers or plates.
jMryn'geal, relating to the Larynx.

" pouches, 279.

Lar'ynx, 248, 259.
" of birds, 279.
" " reptiles, 280.
" its similarity to a reed instru-
ment, 264.
Lead in the body, 7.
Lens of the eye, 374.

life, characteristic of organic substances, 5.
Lig^aments, 69.

^ annular, show design, 423.

" used as braces, 74.

Lime, carbonate and phosphate o^ 11.
Lin'gual nerves, 831, 351.
Liver, 165.
" of mammals, 189.

LoVules of lung, 247.
Lower jaw, 50, 89.
Lumbar arteries, 212.

Lumbar plexus, 834.

Lunglet, lobule of lung.

Lungs, their liability to disease, 265.

" " action essential for health, 266L

" pure air essential to, 266.

" capacity of, as aflfected by posture,

267.
" capacity of may bo increased, 267.
" of mammals, 270.
" " birds, 270.
" " reptiles, 272.
Lymph, 15.
Lymphat'icE, 182, 284.

" their function, 287.

" material absorbed by, 287.

Lymphat'ic hearts, 236.
" glands, 285.

Magne'sium in the body, 7.

Malar bones, 48.

Malle'olus, 64.

Man not without hope, 429.

Manganese' in the body, 7.

Man'dible, 50, 89.

Mantle of Molluscs, 314.

Many-plies, 187.

Marmot, a rodent or gnawing animaL

Mass'eter muscle, 116.

Mastication, 172.

3Ie'dia, or humors.

Medull'a oblonga'ta, 322, 347.

Ifedtt'sce, radiate animals.

Meibo'mian glands, 377.

Membra^na tym'pani, 390.

Membrane, simple, 17.

Mesenter'ic artery, 212.

" glands, 169.

Mes'entery, 168.
3fetamor'phosi,% change.
Metacar'pus, 60, 79, 91.
Metatar'sus, 65.

" of birds, 97.

Milk, 16.

3Iimo^sa, plant of the order leguminosae.
Moisture, its effect upon lymphatics, 289.
Molar teeth, 64.
Mollusca, 85.

" skeleton of, 104.
3/otor, exciting motion.
" nerves, 3o6.
« oculi, 326, 351.
Mouth, 155.

Movements of radiata, 153.
Mu'cus, 15.
Muscles, number of in man. 111.

" suspensory,''152.

" of birds, feathers, 152.

" design shown in them, 421.

" looped, show design, 422.

" need use, 139.

" ." gradual rest, 140.

" require regular exercise, 140.

" time they may be employed, 154

" forms ot; 110.

" of the fore arm, 120.

« " birds, 151.

*' " fishes, 152.

*♦ " articulates and molluscs,

153.
Muscular development, 141.

INDEX AND GLOSSARY,

43^

Muscular strength, examples of, 137, 154.

" contraction, cause of, 135.

" moveuaent, disadvantage of it, 136,

" contraction, its rapidity, 13S.

" " " duration, 13S.

" " " precision, 139.

Mus'culin, 12.

MyoKogy, definition of, 107.
Myotil'ity, 26, 134.

Mystery as great in physiology as in relig-
ion, 432.
Mystery in muscular movement, 432.

" in connection of mind and matter,
432.

N.

Nails, 277.
Nasal bones, 4S.
" duct, 375.
Nasmyth's membrane, 53,
Neck, its length dependent on, 87.

" how to" be dressed, 269.
Nerve tubes and fibers, 317.
" vesicles or cells, 318.
Nerves over sensitive, 42S.
Nervous power shows design, 423.
'-' system, its hy2;iene, 352.
Neurol'ogy, definition olf, 316.
Nictitating membrane, 383.
Ni'trogen, 6.

Mtrog'enoufi, containing nitrogen.
Normal, according to the standard.
Nose, 412.
Nostrils, 415.

" their use in the voice, 265.
Nn'clear, pertaining to a nucleus.
Ifa'clented, IS.
Nucle'olus, IS.
Nu'cleus, IS.

0.
Oil, 16.

'• glands, 299.

" " ' use of, 807.
O'lein, 11.

Olftic'tory nerves, S25, 850.
Oina'sum, 187.
Omen'tnm, 16S.
Optic nerves, 326, 351.
Orbicula-'ris pal'pebrje, 114.

oris, 115.
Organ, definition of. 29.
Organs adai)ted to circumstances, 426.
Omitlioryn' chus, an animal of the class

mammalia.
Os'cillatory, vibrating.
Oss'icleti^ little bones.
Os quadra'tum, 397.
Os'teiii, 12.

Osteol'ogy, definition of, 31,
(>t'oUth.% bony particles of the ear.
Ovalbu'men,. 12.
Ox'ygen in the body, 6.

Pacin'ian coipnscleSj836.
Pal'ate bones, 49.
Palmar arch, 209.
Pau'creas, 166.
Panci-eat'ic fluid, 16.
Papil'lfB, 295, 400, 40S.
Par'asite of skia, 2991

Pari'etal bone, 44.
PatelFa, 63.
Paunch, 187.
Pecten marsu''pium, 3S4.
Pedun'cU, a stalk or stem.
Pedun'culated, having a stalk or peduncle.
Pelvis, bones of, 61.
reii'niform, feathei-^shaped.
Pep'sin, 15, 160.
PericarMium, 204.
Per'ilymph, 391,
Perios'teum, 34.

Peristal'tic, moving like a worm.
Peritone''um, 16S.
Pcrspira'tion, 3ul.
Peyer's patches, 163.
Phalanges, 60, 65, 79, 91, 97.
Pharyn'geal, belonging to the pharynx.
Pha'rynx, 156.
Phos'phorus in the body, 7.
Phvsiolosy, definition of, 6.
Pia' ma'ter, 324.
Pig'ment cells, 295.
Pigmen'tary spots, 385.
Piginen'tiim ni-'grum, 372.
Pinna, 3S9.

Pitic'itary onemhrane^ the lining mem-
brane of the nose.
Placoid'ians, 314.

Pliui, unity of, in animal system, 424.
Plasma, watery portion of the blood.
Plas'tron, 99.
Pleasure superadded to functions when not

necessarv, 425.
Pleura, 248.
Pleurisy, 248.
Plexus, 832.

Pneumogas'tric nerves, 330, 851.
Pneumonol'ogy, definition t.f, 244.
Poison introduced by lymphatics, 2SS.
Pol)jhe'dj-al, witli many ends.
PolypH, radiate animals.
Poplit'eal artery, 213.
Pores of bones, 34.
Portal system, 218, 236.
Potass'ium in the body, 7.
Power reserved for exiicencifts, 426.

" vicarious in organs, 426.

" recuperative in the system, 421,
Prehen'sile, adapted for seizing.
Prehen'sion, the act of grasping.
Primary tissue, 14, 22.
Principles, immediate, grouped, 8, 9.
Prismoid, like a prism.
Pi'Wtine, primary.
Process, an elevation on a bone.
Processes of bones, 35.
Pro'tein, 13.
Psoas muscle, 126.
Pty'alin, 172,
Pu'bis, 61.

Pulsations of heart, 227.
Pylor'ic appendages, 194.
PyU/ruSy tae lower ^ri fioe of tho storaaclj. .

Quadran'ffitlar, with 4 angtea.
Qaadrilat'eral^ " •' sides.

Ea'dial artery, 20S.
Kadia'ta, So.

(438

INDEX AND GLOSSARY

Eadiata, skeleton of, lOG.

Kadicals, organic, 8.

Ba'dius, 59.

Bam'ify, to give off branches.

Eectura, 162.

Ked or Rennet, 188.

Ecflex actions Jn articulates, 363.

Religious applications of anatomy, 420.

Respira''tion, process of, 252.

Respi-'ratorv organs of mammals, 270.

" " " birds, 270.

" " " reptiles, 272.

" " " fishes, 275.

" " " articulates, 276.

" " " molluscs, 278.

» " " radiates, 279.

Retic'ulnm, 186.
Ret'ina, 372.

Retractile, capable of being drawn back.
Ribs, 55, 96.
Rickets, cause of, 82.
Eo'dent, gnawing.
Rota^tion, 68.

Bu'minants, animals that chew the end
like the cow.

s.

Sac'ciform, like a sac.
Sa'cral plexus, 334.
ida'crum, 41.
Sali'va, 16, 172.
Sal'ivary glands, 155.
Salt in the human body, 11.
S(ipona'ceoio>^, soapy.
Sarcolern'ma, 108.
Scales of serpents, 313.

" fishes, 314.
Scap'ula, 57.
Scepter, Indian, 145.
Schindyle'sis, 66.
Science, its highest use, 420.
Seba'ceous glands, 299.
Sclerotica, 369.
JScle'rous, hard like bone.
Secre'tion, vicarious. 292.
after death, 291.
" function of, 291.

" eff'ect of emotions upon, 291.

Seg'menis, divisions.
Semicir'cular canals, 391.
Sensa'tions, effect of habit upon, 368, 402.
Senses often a source of misery, 418.
" dependent on mind, 367.
" effect of excessive use of, 367.
" development in lower animals, 367.
Sensual happiness not perfect, 419.
Seralbu'men, 12.
Serra'ti muscles, 125.
Sc'rum, 15.

Ses'amoid bones, 65, 97.
Sighted, long and short, 8S1.
SiKicon in the body, 7.
Si'nuses, 217.

Skeleton, design showed In, 421.
" human, weight of, 82.
Skin, ^295.

" uses of, 305.

" its hygien^ic value, SOS.

" attention necessary for, 809, 810.

" of mammals, 810.

" " birds, 312.

Skin of amphib'ia, 813.

" " ra'diates, 315.
Sleep, 342, 347.
Smell under control of the tdll, 414.

" sense of. In animals, 414, 416.
So'dium in the body, 7.
Solar plexus, 340.
Solitary glands, 163.
Sound, organs essential for, 264.
Sounds of heart, 227.
" " insects, 280.
" " moUusca, 281.
Special sense, nerves of, 868.
Sphe'noid bone, 45.
Sphinc'ter, 111.
Spinal cord, 322, 332, 348.

" column, 42, 78, 85.

" nerves, 332, 352, 358.

" accessory nerve, 330, 851.
Spi^racles of insects, 276.
Splanchnology, 155.
Spleen, 293.
Sple'nic artery, 212.
SteU'ate, star-shaped.
Stem'mata, 387.
Sternum, 55, 96, 101.
Sterno-cleido mastoid muscle, 116.
Stim-'ulants, their value and injury, 135.
Stomach, 158.

" of ruminants, 187.
" " birds, 190.
Styloid bones, 89.
Subcia'vian artery, 206.
Sugar in the body, 11.
Sulphur " " T.
Superior Max'illary, 50.
Suppura'tion, forming of pus-
Suspen'sory muscle, 152.
Sutu'ra, 66.
Su'tures, 46.
Sweat, 17.

" glands, 299.
Sympathet^ic system, 337, 848, 853.

" ganglia, a39.

Sympathy between heart and lungs, 245.
Sym'physes, 67.
Synarthro'sis, 66.
Syn'ehronou.% at the same time.
Syndesmol'ogy, definition of, 66.
Syno'vial membrane, 73.
Systems of organization mutually depend-
ent, 424.
Sys'tole, 226.

T.

Tac/tile, susceptible of touch.
Tailor's muscle, 129.
Tape'tum, 383.
Tarso-metatar'sus, 97.
Tarsus, 64, 81.
Taste, nerves of, 407.

" effect of education upon, 403.

" - its connection with amell, 40S.

*' a guide for the appetite, 418.
Tears, 16, 880.
Teeth, human, 51.

" esophage'al, 192.

" of reptiles, 191.

" of fishes, 102.

" development of, 58.

" names of, 54, 90.

" fracture of, 54.

INDEX AND OLOSSART

43^

Teeth, care needed for, 82.

" generally decay early in Ufa, 83.
Teg'ument of articulata, 314.
Tegument' ary, relating to the skin.
T^guraenfary muscle, 150.
lemperature of human body, 257.
Tem'poral bone, 43.

" muscle, 116.
Tendons of fingers and toes, 120.

" ossification of, in birds, 151.
Tensitr vag'infe fem-'oris, 129.
Tento'rium, 358.
ThaKami op'lici, 322.
Thoracic, pertaining to the chest.
Thorac'ic duct, 170.
" aorta, 211.
Thy'roid cartilage, 260.
Tib'ia, 63.
Tib'iai artery, 213.
Time during which .muscles can be used-

154.
Tissue, simple fibrous, 22.

" white fibrous, 22.

" yellow " 22.

" areolar, 23.

" fibro-cellular, 23.

" cellular, 24.

" sclerous, 24.
tubular, 25.

" muscular, 26.

" nervous, 28.
Tobacco, its efl'ect on the brain, 355.
Tongue, human, 406.
" of reptiles, 191.
" use of, in speech, 265.
Tonic'ity, muscular, 134.
Tonsils, 155.
Tortoise shell, 99.
Touch, instruments of, 400.

" of lower animals, 403, 405.
Tra'chea, 248.

" of mammals, 270.
" " insects, 276.
Transverse, crosswise.
Transuda'tions, 15.
Triangle for exercise, 145.
Triceps muscle, 119.
Trifa'cial nerves, 326, 351.
Trill of birds, 279.
Triquet^ra ossa, 47.
Trochan'ter process npon the upper part

of the femur.
Troch-'Iear nerves, 326.
Tuberc'ula quadrigem'ina, 322.
Tur'binal bone, 49.
Tym'panic bones, 88.
Tym'panura, 390.

TT.

TJlcera'tion, ulcer-forming.

Ulna, 58.

Ulnar artery, 208.

Unicellular animals, 199.

Uniformity of animal heat, 258.

Unity, Divine, proofs of from anatomy, 430.

" " proved by the conspiration

of all the parts, 430.
Unity proved by mutual relation, 430.
Urine, 16.

V.

"Valves of the heart, 203.
Veins, 217.

" valves of, their discoverer, 219.
Yentral trunk, 241.
Ven'tricles, 202.

" of brain, 324.

Ventu-'ri, principle of, 181.
Ver''tebra, cervical, 40, 85, 93.
dorsal, 41, 85, 93.

" lumbar, 41, 85.

" sacral, 85.

" caudal, 85, 93.

Ver'tebral artery, 209.
Vertebra'ta, 85.
Vessels protected, 423.
Ves'tibule, 391,

Vibra'tile, susceptible of vibration.
Villi, hair-like appendages.
Viscera, contents of an animal carity.
Viscid, thick like syrup.
Vision, limits of, 382.
Vitaliza'tion, the act of giving life.
Vitreous humor, 375.
Vocal cord, 262.
Voice, organs of, 259.

" its strength dependent on, 269.
Voluntary motions, on what dependent

340.
Vo'mer, 51.

w.

"Waste the cause of muscular contraction.
135.

Water in the body, 10.

" amount consumed by an adult, 11,
" " discharged by the skin, 3021

Wax, 16.

Wonder nets, 231, 234.

Wounds of arteries, 229.

World fallen, proof of, from anatomy, 429L

INDEX OF CUTS

87

PAGE

Blood Cetstals 9

10

" " 13

Milk r 16

Simple Fiber 17

Cells 18

" 18

Cattdate Cells 19

Stellate " 19

Development of Cells 20

" 20

" " " 21

White Fibrous Tissue 22

Yellow " " 22

Areolar Tissue 23

Cells of Areolae Tissue 23

Adipose Tissue 24

Cartilaginous Tissue 24

Osseous " 25

Lacuna of Bone 25

Lymphatic Vessel 26

Muscular Tissue 26

Diagram op Muscular Fibril.. 26

Muscular Tissue 27

" 2T

" 27

Tubular Nerve Tissue 28

Vesicular " " 28

" " " 29

Fibula after Immersion in Mu-
riatic Acid 32

Canaliculi of Bone 83

Lacuna " " 34

Ultimate Granules of Bone.. 34

Periosteum 85

Development of Cartilage ... 87

Knee Joint 88

Lateral View of Spinal Col.. 88

View of HuMA^f Skeleton 89

Atlas 40

AxTS 43

A Doesal Vertebea 41

Sacrum 41

PA<JB

Coccyx 41

A Dissected Skull 43

Frontal Bone 43

Temporal " 44

Parietal " 44

Occipital " 45

Sphenoid " 45

Ethmoid " 46

Vault of the Cranium 46

Front View op the Skull .... 47

Nasal Bones 48

Malar Bone 48

Lachrymal Bone 49

Palate " 49

TURBINAL " 49

Maxillary " 60

Mandible 50

Vomer 51

Section of Human Incisor 53

" " " Bicuspid.... 52

" " " Incisor .... 52

" " " Molar 52

Enamel of Tooth 53

Permanent Teeth 54

Hyoid Bone 55

Sternum 55

Upper Eib 55

Ribs 56

Bones of the Chest 56

Clavicle 57

Scapula 58

Humerus 58

Fore-Arm 59

Carpal Bones GO

Bones of the Hand 60

Pelvis 61

Innominatum 63

Femur 63

Patella 65

Tibia and Fibula 64

Bones of the Foot 64

Development of Cartilage OD

Ligaments of the Pelvis TO

INDEX OF CUTS.

441

FIG. J"'*-<^E

86 Ligaments of the Shotildek. ... 70

87 " *' '• Hip 71

88 " " " Knee 71

89 " " " Lower Jaw. 72

90 " " " Vebtebe^

AND KiBS 72

91 Ligaments of the Elbow 72

92 " " " Ankle 73

93 " " " Foot 73

94 " " " Ankle 74

95 Skeleton of Caxel 86

96 " " Bat 86

97 " " Cameleopakd 87

93 " " Mole 88

99 Head of Horse 89

100 Teeth ofLion 90

101 Teeth of an Herbivorous Ani-

mal 91

102 Teeth of an Inseotivoe. Animal 91

103 Anterior Extremities of Dif-

ferent Animals 92

104 Hind Foot of Horse 92

105 Foot of Stag 92

106 Skeleton of Swan 94

107 " " G(ELAND 95

108 Head of Eagle 95

109 Bones of Sternum & Shoulder. 96

110 Skeleton of Tortoise 99

111 " " Frog 100

112 " " Perch... 101

113 Section of the Scale of Lepi-

DOSTEUS 101

114 Head of the Pike 102

115 " " " Shark 102

116 Microscopic Structure op

Tooth of Eagle Kay 103

117 Microscopic Structure of Spine

OF Hedgehog 104

118 Microscopic View of Shell of

Pinna 105

119 MicROSC. View of Shell of Mya 105

120 Development of Muscul. Fiber 107

121 Fragments " " " 108

122 Muscular Fibril 108

123 Section of Fibril 109

124 Myolemma 109

125 Cells of Muscular Fiber. . . . . 109

126 Radiate Muscle 110

127 Fusiform " ..110

123 Doubly Pennifobm Muscle 111

129 MuscuLAB System 112

130 " " 113

131 Transverse Section of Neck. . . 114

133 Muscles of Face and Neck 115

133 " " " " " Side

View..... 117

FIG. PAGE

134 Muscles of Back 118

135 » " Arm 119

136 " " Hand & Fore-Arm. 120

137 " " Palm OF Hand 121

138 " " Fore-Arm (deep
Layer) 121

139 Muscles of Back 1 23

140 Diaphragm 125

141 Muscles of Trunk (Side View). 126

142 ' " " Abdomen 127

143 " " Thigh 123

144 " " " (Back View).. 130

145 " " Front OF Leg 130

146 " " Back of Leg 131

147 " '■' Foot 132

148 " " Back of Fore-Arm. 183

149 " " Front OF Leg 133

150 Diagram of Fibrill^e. 134

151 " " Disadvantage of
Muscular Action 136

152 Muscular Fiber Contracting.. 137

153 Back Board 144

154 " " IN Use 145

155 Indian Club 145

156 Uses of Indian Club 146

157 Triangle 145

158 Use of Triangle 145

159 Apparatus of a Gymnasium. . . . 147

160 " " " .... US

161 " " " .... 149

162 Fibrils of Pig 151

163 " " Meat Fly 153

164 Insect Fasciculi 153

165 Salivary Glands 156

166 Follicles from Tonsils. 156

167 Section of Mouth and Pharynx 157

168 Esophageal Glands 153

169 Human Stomach 158

170 Coats OF " 159

171 DiAGR. OF Stomach & Intestines 160

172 Gastric Glands 160

173 C^cuM AND Appendix 161

174 Human Digestive Apparatus,. 163

175 Peyer's Patches 104

176 Brunner's Gland 164

177 Villi of Jejunum 104

178 Human Liver 106

179 Lobule of Liver 1G6

180 Gallbladder :. ^..... 107

181 Pancreas and Spleen "... .'. 167

182 Peritoneum........... .'... 16S

183 Chtliferous Vessels 169

184 Thoracic Duct. 170

185 Kidney 171

186 Diagram of UtiiNARY Appara-

tus..... 171

442

INDEX OF CUTS

FIG.

187

183
189
190
191
192
193
194
195
196
197
198
199
200
201

205

210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228

229
230
231

234

235

237

23.«

PAGE

DiAGKAM OF Position of Thora-
cic Duct and Jugclae Vein.. 181

Principle of Ventuki 182

Digestive Apparatus op Ape... 186

Stomach OF Sheep 187

Interior OF " 1S7

Stomach of Ox 188

Head of Woodpecker 189

Digestive Apparatus of Fowl 190

Head of Kattlesnake 191

Anatomy of Snake 193

Digestive Apparatus of Beetle 194
Viscera of Aplysia (Mollusc). 195

" " Star Fish 195

Fresh Water Polyp 197

Digestive Apparatus of uni-
cellular Animals 198

Human Heart 201

Fibers of the Heart 202

Heart and Lungs 202

Diagram of Heart 203

Valves of Heart 204

" '• Aorta 204

Arterial System 205

Middle Coat of Arteries 206

Heart and Arteries in Situ 207

Arteries of Neck <b Shoulder . 208

" " Arm AND Hand 209

Circle of Willis 210

Abdominal Aorta

Femoral Artery

Arteries of Backside of Leg.
Capillaries

Veins of Face and Neck

" " Trunk and Neck. . .

211
212
213
214
215
216

Sinuses of Brain 217

Valves OF Veins 218

Veins of Arm 219

" " Leg 220

Blood Crystals 221

Ked Blood Corpuscles 221

Diagram of Heart's Contract.. 227

Circulation in Mammals 230

Diagram of Varieties of Aorta

IN Mammals 231

Blood Corpuscles of Ox 231

Blood Crystals of Guinea Pig. 232

Arteries of the Grebe 233

Pigeon Blood Corpuscles 284

Diagr. or Circulat. or Reptiles 234

Blood Corpuscles of Frog 234

Circulat. Apparatus or Lizakd 235

Heart of Crocodile 286

" " Turtle.. 236

Diagram of Circulat. of Fishes 287
CiRCULATiKG Vessels in the Fish 233

fig.
240
241
242

243
244
245

246
247
248
249
250

251
252
253
254
255
256
257
253
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
2S5
286
287

290
291
292

PAGB

Blood Corpuscles of Eel 239

Plan of Circulation in Fishes. 289
Circulatory Appapatus of the

Lobster 240

Circulat. Apparatus of Insects 240

Blood Corpuscles of Crab 241

Anatomy of the Snail. 242

Heart and Lungs 244

Bronchi and Vessels in Situ. . . 246

Thoracic Viscera in Situ 246

LUNGLET 247

DiAGRAMATIC SECTION OF THORA-
CIC Viscera 249

Capillaries of Human Lung... 250

Magnified Section of Lung 250

Termination of Bronchus 251

Bronchial Tube laid open 251

Lateral View of Larynx 259

Thyroid Cartilage 260

Arytenoid " 260

Cricoid " 261

Epiglottis 261

Larynx 261

262

262

Larynx and Epiglottis 263

Lungs OF A Bird 271

Lungs, etc., of a Pigeon 271

LUNGLET OF A FoWL 272

Lungs of a Frog 272

" " Serpents 273

Dissected Lung of Turtle 274

Gills of Eel 274

Air Bladder of Fish 275

Trachea of Water Scorpion... 276

Spiracle of Fly 277

Lymphatics 282

Lymphatic System 283

Lymphatics of Axilla 284

Thoracic and Lymphatic Ducts 285

Lymphatics of Abdomen 286

" " Thigh 287

Diagram OF A Gland 290

Chyliferous Vessels 290

The Spleen 293

Intimate Structure of Spleen. 293

" " " « 293

294

Papilla or Hand 295

Epidermis of Negko 298

Pigment Cells 296

Section or Thumb 297

Cerumen Gland 29D

Parasites OF the Fat Glands.. 300

Skin OF Palm OF Hand 301

Pebspieatoey Gland 8C]

INDEX 0 F CUTS.

443

no. PAGB

294 Sections op Human Haik 302

295 Skin OF Scalp 303

296 RootofHaib 304

297 Haib of Human Beard 305

298 " " Sable 311

299 « " MuskDeee 311

300 " " Squieeel 312

801 " " Pecari 312

802 TtTBULAR Nerve Cells 317

303 Vesicular " « 318

304 Section of Brain, etc 319

805 " " " 320

306 Cerebellum... 320

307 Base of Brain 321

308 Cerebeo-Spinal Axis 322

309 Sinuses of Brain 323

310 Olfactory Nerves 325

311 OpticNerves , 326

812 Third, Fourth, and Sixth Cra-

nial Nerves 327

813 Trifacial Nerve 327

314 " " ..o 328

815 Auditory " 328

316 Tenth Pair of Nerves 329

317 Nerves of Tongue, etc 330

818 Portion of Spinal Cord 331

319 Diagram showing Decussation 332

820 Nervous System 333

821 Brachial Plexus. 334

822 Nerves of Fore- Arm 334

823 Ischiatio Plexus 335

824 Crural Nerve, etc 835

825 Nerves of the Foot 336

826 Pacinian Corpuscles 836

327 Sympathetic Nerve. 838

828 Union of Spinal and Sympa-

thetic Nerve 339

829 Brain of Squirrel. §57

830 " " Rabbit 357

331 " « Buzzard 859

832 « « Turtle 360

833 " " Fishes..... 361

834 Electbicai. Appab. of Tobpedo. 862

FIG

335

340

341
342
343
344

345

346
347
348
349
350

351
352
353
854
355
356
857

360
361

364
365
366
367

370
371
872
873

PAGE

Nervous System of Articulates 362

" •• " Beetle 363

" " " Argonauta 364

Nervous System op Star Fish.. 365

Globe OP THE Eye 870

Plan of the Structure of the

Eye 371

Choroid Coat 371

The Iris 372

The Eye Dissected 373

Microscopic Section op the Ee-

TIN A 373

Crystalline Lens, Front View 874
" " Side View.. 374

Lens AT Different Ages 374

Eyelids & Lachrymal Glands.. 875

Lachrymal Canals 376

View of Eye and Append-
ages 876

Meibomian Glands 377

A Single Meibomian Gland,... 377

Muscles of the Eye 877

Head and Eye of the Bee 386

Section of one Facet 886

Eye of Trilobite 387

The Left Ear 389

External and Internal Ear . . 389

Cavity op THE Tympanum 890

Membrana Tympani. 391

Ossicula Auditus 391

Labyrinth and Tympanum .... 392
Cochlea without the Nerve, . . 392
Nerve without the Cochlea. . . 393
Nerves of Extremity op Thumb 400

Papilla of thb Palm 400

Foot OF A Fly 405

Human Tongue 406

Papilla op Tongue 40T

Head OP "Woodpecker 410

Tongue of Fly 411

Cartilages of Nose 412

Skction of Nostbils 413